Let us begin simply with the following: \begin{examplebox} \subsection{Examples:} \begin{questions} \Question[1] Express as a power or as a product of powers. \begin{parts} \part \(5 \times 5 \times 5\) \begin{solutionordottedlines} \(5 \times 5 \times 5=5^{3} \quad\) \end{solutionordottedlines} \part \(3 \times 3 \times 7 \times 7 \times 7 \times 7\) \begin{solutionordottedlines} \(3 \times 3 \times 7 \times 7 \times 7 \times 7=3^{2} \times 7^{4}\) \end{solutionordottedlines} \part \end{parts} \Question[1] Express each number as a power of a prime. \begin{parts} \part 81 \begin{solutionordottedlines}[2cm] \(\quad 81=3 \times 3 \times 3 \times 3\) \end{solutionordottedlines} \part 128 \begin{solutionordottedlines}[2cm] \(128=2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 2\) \(=3^{4}\) \(=2^{7}\) \end{solutionordottedlines} \end{parts} \end{questions} \end{examplebox} Now some definitions: \begin{boxdef} \textbf{Base:} \begin{solutionordottedlines}[1cm] The number 2 in \(2^{4}\) is called the base. \end{solutionordottedlines} \end{boxdef} \begin{boxdef} \textbf{Index:} \begin{solutionordottedlines}[1cm] The number 4 in \(2^{4}\) is called the index or exponent. \end{solutionordottedlines} \end{boxdef} \begin{boxlaw} \subsection*{Index Laws} \subsubsection*{Product of Powers} To multiply powers of the same base, add the indices. \[ a^{m} a^{n}=a^{m+n} \] \subsubsection*{Division of Powers} To divide powers of the same base, subtract the indices. \[ \frac{a^{m}}{a^{n}}=a^{m-n} \quad \text { where } m>n \text { and } a \neq 0 \] \subsubsection*{Powers of Powers} To raise a power to a power, multiply the indices. \[ \left(a^{m}\right)^{n}=a^{m n} \] \subsubsection*{Power of Products} A power of a product is the product of the powers. \[(a b)^{m}=a^{m} b^{m}\] \subsubsection*{Power of Quotient} A power of a quotient is the quotient of the powers. \[ \left(\frac{a}{b}\right)^{m}=\frac{a^{m}}{b^{m}} \quad \text { where } b \neq 0 \] \subsubsection*{Zero Exponent Law} Any base raised to the power of $0$ is equal to $1$. \[a^0 = 1\] \subsubsection*{Negative Exponent Law (next lesson)} \[ a^{-n} = \frac{1}{a^n} \] A negative exponent indicates the reciprocal of the base raised to the corresponding positive exponent. \end{boxlaw} Now with these laws in mind, try the following 10 examples: \begin{examplebox} \subsection{Examples} \begin{questions} \Question[10] Simplify, expressing the answer in index form. \begin{parts}\begin{multicols}{2} \part \(3^{2} \times 3^{4}\) \begin{solutionordottedlines}[2cm] \(3^{2} \times 3^{4}=3^{6}\) \end{solutionordottedlines} \part \(a^{3} \times a^{5}\) \begin{solutionordottedlines}[2cm] \(a^{3} \times a^{5}=a^{8}\) \end{solutionordottedlines} \part \(3 x^{2} \times x^{3}\) \begin{solutionordottedlines}[2cm] \(3 x^{2} \times x^{3}=3 x^{5}\) \end{solutionordottedlines} \part \(2 a^{2} b^{3} \times 5 a b^{2}\) \begin{solutionordottedlines}[2cm] \(2 a^{2} b^{3} \times 5 a b^{2}=10 \times a^{2+1} \times b^{3+2}\) \[ =10 a^{3} b^{5} \] \end{solutionordottedlines} \part \(\frac{3^{5}}{3^{2}}\) \begin{solutionordottedlines}[2cm] \(\frac{3^{5}}{3^{2}}=3^{5-2}\) \end{solutionordottedlines} \part \(\frac{9^{5}}{9^{4}}\) \begin{solutionordottedlines}[2cm] \(\frac{9^{5}}{9^{4}}=9^{1}\) \end{solutionordottedlines} \part \(10^{6} \div 10^{4}\) \begin{solutionordottedlines}[2cm] \(10^{6} \div 10^{4}=10^{6-4}\) \(=3^{3}\) \(=9\) \(=10^{2}\) \(=27\) \(=100\) \end{solutionordottedlines} \part \(a^{7} \div a^{4}\) \begin{solutionordottedlines}[2cm] \(\begin{aligned} a^{7} \div a^{4} & =a^{7-4} \\ & =a^{3}\end{aligned}\) \end{solutionordottedlines} \part \(\frac{3 y^{4}}{y}\) \begin{solutionordottedlines}[2cm] \(\frac{3 y^{4}}{y}=3 \times \frac{y^{4}}{y}\) \end{solutionordottedlines} \part \(\frac{6 x^{5}}{2 x^{3}}\) \begin{solutionordottedlines}[2cm] \(\frac{6 x^{5}}{2 x^{3}}=\frac{6}{2} \times \frac{x^{5}}{x^{3}}\) \(=3 \times y^{4-1}\) \(=3 \times x^{5-3}\) \(=3 y^{3}\) \(=3 x^{2}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4] Double marks for each of these: \begin{parts} \part \[\frac{3 x^{3} y^{2}}{4 x y} \times \frac{6 x^{2} y^{3}}{x^{3} y^{2}}\] \begin{solutionordottedlines}[2cm] \(\frac{3 x^{3} y^{2}}{4 x y} \times \frac{6 x^{2} y^{3}}{x^{3} y^{2}}=\frac{18 x^{5} y^{5}}{4 x^{4} y^{3}}\) \(=\frac{9 x y^{2}}{2}\) \end{solutionordottedlines} \part \[\frac{8 a^{2} b^{3}}{3 a^{3} b} \div \frac{4 a b^{2}}{9 a^{3} b^{5}}\] \begin{solutionordottedlines}[2cm] \(\frac{8 a^{2} b^{3}}{3 a^{3} b} \div \frac{4 a b^{2}}{9 a^{3} b^{5}}=\frac{8 a^{2} b^{3}}{3 a^{3} b} \times \frac{9 a^{3} b^{5}}{4 a b^{2}}\) \[ =\frac{72 \times a^{5} \times b^{8}}{12 \times a^{4} \times b^{3}} \] \[ =6 a b^{5} \] \end{solutionordottedlines} \end{parts} \Question[6] And a $1.5\times$ multiplier for these: \begin{parts} \part \(\left(\frac{2}{3}\right)^{2}\) \begin{solutionordottedlines}[2cm] \(\begin{aligned}\left(\frac{2}{3}\right)^{3} & =\frac{2^{3}}{3^{3}} \\ & =\frac{8}{27}\end{aligned}\) \end{solutionordottedlines} \part \(\left(\frac{m}{n}\right)^{5}\) \begin{solutionordottedlines}[2cm] \(\left(\frac{m}{n}\right)^{5}=\frac{m^{5}}{n^{5}}\) \end{solutionordottedlines} \part \(\left(\frac{x^{3}}{y^{2}}\right)^{2} \times\left(\frac{y}{x}\right)^{4}\) \begin{solutionordottedlines}[2cm] \(\left(\frac{x^{3}}{y^{2}}\right)^{2} \times\left(\frac{y}{x}\right)^{4}=\frac{x^{6}}{y^{4}} \times \frac{y^{4}}{x^{4}}\) \end{solutionordottedlines} \part \(\left(\frac{2 x^{2}}{3}\right)^{2} \div \frac{4 x^{3}}{9}\) \begin{solutionordottedlines}[2cm] \(\left(\frac{2 x^{2}}{3}\right)^{2} \div \frac{4 x^{3}}{9}=\frac{4 x^{4}}{9} \times \frac{9}{4 x^{3}}\) \(=x^{2}\) \(=x\) \end{solutionordottedlines} \end{parts} \begin{parts} \part \(\left(5 a^{3}\right)^{0}\) \begin{solutionordottedlines}[2cm] \(\left(5 a^{3}\right)^{0}=1\) \end{solutionordottedlines} \part \(\frac{6 x^{2} y}{x y^{2}} \times \frac{y^{3} x}{2 y^{2} x^{2}}\) \begin{solutionordottedlines}[2cm] \[ \begin{aligned} \frac{6 x^{2} y}{x y^{2}} \times \frac{y^{3} x}{2 y^{2} x^{2}} & =\frac{6}{2} \times \frac{x^{3}}{x^{3}} \times \frac{y^{4}}{y^{4}} \\ & =3 x^{0} y^{0} \\ & =3 \times 1 \times 1 \\ & =3 \end{aligned} \] \end{solutionordottedlines} \part \(\left(m n^{2}\right)^{0}\) \begin{solutionordottedlines}[2cm] \(\left(m n^{2}\right)^{0}=1\) \end{solutionordottedlines} \part \(\left(a^{4} b^{2}\right)^{3}\) \begin{solutionordottedlines}[2cm] \(\left(a^{4} b^{2}\right)^{3}=a^{12} b^{6}\) \end{solutionordottedlines} \part \(\left(2 a^{4}\right)^{3}\) \begin{solutionordottedlines}[2cm] \(\left(2 a^{4}\right)^{3}=2^{3} \times a^{12}\) \end{solutionordottedlines} \part \(2\left(x^{2} y\right)^{0} \times\left(x^{2} y^{3}\right)^{3}\) \begin{solutionordottedlines}[2cm] \(2\left(x^{2} y\right)^{0} \times\left(x^{2} y^{3}\right)^{3}=2 \times 1 \times x^{6} y^{9}\) \(=8 a^{12}\) \(=2 x^{6} y^{9}\) \end{solutionordottedlines} \part \end{parts} \end{questions} \end{examplebox} \fbox{\fbox{\parbox{\textwidth}{\textbf{Note: }There are different possible interpretations of the word 'simplify'. There may be more than one acceptable simplified form. }}} \begin{exercisebox} \subsection{Exercises:} \begin{questions} \Question[3] State the base and index of: \begin{parts}\begin{multicols}{3} \part \(6^{4}=\fillin[6]\) \begin{solutionordottedlines} Base: 6, Index: 4 \end{solutionordottedlines} \part \(7^{3}=\fillin[7]\) \begin{solutionordottedlines} Base: 7, Index: 3 \end{solutionordottedlines} \part \(8^{2}=\fillin[8]\) \begin{solutionordottedlines} Base: 8, Index: 2 \end{solutionordottedlines} \end{multicols}\end{parts} \Question[3] Express as a power of a prime number. \begin{parts}\begin{multicols}{3} \part $8 = \fillin[$2^3$]$ \part $27 = \fillin[$3^3$]$ \part $64 = \fillin[$2^6$]$ \end{multicols}\end{parts} \Question[3] Evaluate: \begin{parts}\begin{multicols}{3} \part \(3^{4}=\fillin[81]\) \part \(2^{7}=\fillin[128]\) \part \(5^{5}=\fillin[3125]\) \end{multicols}\end{parts} \Question[3] Express as a product of powers of prime numbers. \begin{parts}\begin{multicols}{3} \part $18=\fillin[$2 \times 3^2$]$ \part $24=\fillin[$2^3 \times 3$]$ \part $144=\fillin[$2^4 \times 3^2$]$ \end{multicols}\end{parts} \Question[3] Simplify: \begin{parts}\begin{multicols}{3} \part \(2^{7} \times 2^{3}\) \begin{solutionordottedlines} \(2^{10}\) \end{solutionordottedlines} \part \(3^{3} \times 3^{4} \times 3^{5}\) \begin{solutionordottedlines} \(3^{12}\) \end{solutionordottedlines} \part \(3 x^{2} \times 4 x^{3}\) \begin{solutionordottedlines} \(12 x^{5}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4] Simplify: \begin{parts}\begin{multicols}{2} \part \(a^{2} b^{3} \times b^{2}\) \begin{solutionordottedlines} \(a^{2} b^{5}\) \end{solutionordottedlines} \part \(a^{3} b \times a^{2} b^{3}\) \begin{solutionordottedlines} \(a^{5} b^{4}\) \end{solutionordottedlines} \part \(2 x y^{2} \times 3 x^{2} y\) \begin{solutionordottedlines} \(6 x^{3} y^{3}\) \end{solutionordottedlines} \part \(4 a^{3} b^{2} \times a^{2} b^{4}\) \begin{solutionordottedlines} \(4 a^{5} b^{6}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[6]$\,$ \begin{parts}\begin{multicols}{2} \part \(\frac{3^7}{3^2}\) \begin{solutionordottedlines} \(3^5\) \end{solutionordottedlines} \part \(\frac{2^{6}}{2^{2}}\) \begin{solutionordottedlines} \(2^4\) \end{solutionordottedlines} \part \(10^{7} \div 10^{2}\) \begin{solutionordottedlines} \(10^5\) \end{solutionordottedlines} \part \(\frac{10^{12}}{10^{4}}\) \begin{solutionordottedlines} \(10^8\) \end{solutionordottedlines} \part \(\frac{2 x^{3}}{x^{2}}\) \begin{solutionordottedlines} \(2 x\) \end{solutionordottedlines} \part \(\frac{6 x^{5}}{2 x^{2}}\) \begin{solutionordottedlines} \(3 x^{3}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4]$\,$ \begin{parts}\begin{multicols}{2} \part \(\frac{a^{3} b^{2}}{a^{2}}\) \begin{solutionordottedlines} \(a b^{2}\) \end{solutionordottedlines} \part \(\frac{x^{3} y^{2}}{x y}\) \begin{solutionordottedlines} \(x^{2} y\) \end{solutionordottedlines} \part \(\frac{12 a^{6} b^{2}}{4 a^{2} b}\) \begin{solutionordottedlines} \(3 a^{4} b\) \end{solutionordottedlines} \part \(\frac{15 x y^{3}}{3 y^{2}}\) \begin{solutionordottedlines} \(5 x y\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4]$\,$ \begin{parts}\begin{multicols}{2} \part \(\frac{a^{3} b^{2}}{a b} \times \frac{a^{2} b}{a}\) \begin{solutionordottedlines} \(a^{4} b^{2}\) \end{solutionordottedlines} \part \(\frac{x^{3} y}{x y^{2}} \times \frac{x^{4} y^{5}}{x^{2}}\) \begin{solutionordottedlines} \(x^{4} y^{4}\) \end{solutionordottedlines} \part \(\frac{6 a b^{2}}{5 a^{3} b} \div \frac{12 a b}{15 a^{5} b}\) \begin{solutionordottedlines} \(3 a^{2} b\) \end{solutionordottedlines} \part \(\frac{7 x^{3} y^{4}}{2 x y^{2}} \div \frac{21 x^{2} y^{3}}{4 x^{3} y^{2}}\) \begin{solutionordottedlines} \(2 x^{2} y\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[6]$\,$ \begin{parts}\begin{multicols}{3} \part \(a^{4} \times \fillin[$a^{6}$]=a^{10}\) \begin{solutionordottedlines} \(a^{6}\) \end{solutionordottedlines} \part \(9 d^{5} \times \fillin[3]=27 d^{6}\) \begin{solutionordottedlines} \(3 d\) \end{solutionordottedlines} \part \(15 d^{7} \div \fillin[$5 d^{5}$]=3 d^{2}\) \begin{solutionordottedlines} \(5 d^{5}\) \end{solutionordottedlines} \part \(8 a b^{4} \times \fillin[$3 a b^{2}$]=24 a^{2} b^{6}\) \begin{solutionordottedlines} \(3 a b^{2}\) \end{solutionordottedlines} \part \(\ell^{6} m^{7} \div \fillin[$\ell^{4} m^{2}$]=\ell^{2} m^{5}\) \begin{solutionordottedlines} \(\ell^{4} m^{2}\) \end{solutionordottedlines} \part \(b^{7} \times \fillin[$b^{9}$]=b^{16}\) \begin{solutionordottedlines} \(b^{9}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[2]$\,$ \begin{parts}\begin{multicols}{2} \part \(a^{0}\) \begin{solutionordottedlines} \(1\) \end{solutionordottedlines} \part \(2 x^{0}\) \begin{solutionordottedlines} \(2\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[6]$\,$ \begin{parts}\begin{multicols}{3} \part \(3 a^{0}\) \begin{solutionordottedlines} \(3\) \end{solutionordottedlines} \part \(6 a^{0}\) \begin{solutionordottedlines} \(6\) \end{solutionordottedlines} \part \(4 a^{0}+3 b^{0}\) \begin{solutionordottedlines} \(7\) \end{solutionordottedlines} \part \(6 a^{0}+7 m^{0}\) \begin{solutionordottedlines} \(13\) \end{solutionordottedlines} \part \((4 b)^{0}+2 b^{0}\) \begin{solutionordottedlines} \(3\) \end{solutionordottedlines} \part \((3 b)^{0}-5 d^{0}\) \begin{solutionordottedlines} \(-4\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[2] Simplify, leaving the answer as a power. \begin{parts}\begin{multicols}{2} \part \(\left(2^{3}\right)^{4}\) \begin{solutionordottedlines} \(2^{12}\) \end{solutionordottedlines} \part \(\left(3^{2}\right)^{3}\) \begin{solutionordottedlines} \(3^{6}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4] $\,$ \begin{parts}\begin{multicols}{2} \part \(\left(a^{3}\right)^{2} \times\left(a^{3}\right)^{4}\) \begin{solutionordottedlines} \(a^{14}\) \end{solutionordottedlines} \part \(\left(x^{4}\right)^{2} \times\left(x^{3}\right)^{3}\) \begin{solutionordottedlines} \(x^{17}\) \end{solutionordottedlines} \part \(2 a b^{2} \times 3 a\left(b^{3}\right)^{2}\) \begin{solutionordottedlines} \(6 a^{2} b^{8}\) \end{solutionordottedlines} \part \(\frac{3 a b}{\left(b^{2}\right)^{3}} \times \frac{4 b^{7}}{3 a}\) \begin{solutionordottedlines} \(4 b^{2}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4]$\,$ \begin{parts}\begin{multicols}{2} \part \((3 a)^{2}\) \begin{solutionordottedlines} \(9 a^{2}\) \end{solutionordottedlines} \part \((2 x)^{3}\) \begin{solutionordottedlines} \(8 x^{3}\) \end{solutionordottedlines} \part \(\left(\frac{a}{5}\right)^{2}\) \begin{solutionordottedlines} \(\frac{a^{2}}{25}\) \end{solutionordottedlines} \part \(\left(\frac{2}{x}\right)^{3}\) \begin{solutionordottedlines} \(\frac{8}{x^{3}}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4]$\,$ \begin{parts}\begin{multicols}{2} \part \(\left(2 a^{2} b\right)^{2} \times 3 a b^{3}\) \begin{solutionordottedlines} \(12 a^{5} b^{5}\) \end{solutionordottedlines} \part \(\left(3 x y^{2}\right)^{3} \times\left(x^{2} y\right)^{2}\) \begin{solutionordottedlines} \(27 x^{5} y^{8}\) \end{solutionordottedlines} \part \(\left(5 x y^{2}\right)^{3} \times\left(x^{2} y^{3}\right)^{2}\) \begin{solutionordottedlines} \(125 x^{7} y^{13}\) \end{solutionordottedlines} \part \(\left(2 a^{3} b\right)^{3} \times 3 a^{0}\) \begin{solutionordottedlines} \(24 a^{9} b^{3}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4]$\,$ \begin{parts}\begin{multicols}{2} \part \(\left(\frac{x^{2}}{y}\right)^{2} \times\left(\frac{y^{2}}{x}\right)^{3}\) \begin{solutionordottedlines} \(\frac{x y^{4}}{y^{2}}\) \end{solutionordottedlines} \part \(\left(\frac{4 a^{2}}{b}\right)^{2} \times\left(\frac{b}{2 a}\right)^{3}\) \begin{solutionordottedlines} \(\frac{8 a b}{b^{2}}\) \end{solutionordottedlines} \part \(\frac{\left(3 x y^{2}\right)^{2} \times\left(2 x^{2} y\right)^{3}}{\left(6 x^{2} y\right)^{2}}\) \begin{solutionordottedlines} \(x^{2} y^{4}\) \end{solutionordottedlines} \part \(\frac{3 a^{2} b^{4} \times\left(2 a b^{2}\right)^{3}}{\left(4 a^{2} b^{3}\right)^{2}}\) \begin{solutionordottedlines} \(\frac{3 a^{2} b^{2}}{4}\) \end{solutionordottedlines} \end{multicols}\end{parts} \end{questions} \end{exercisebox}