\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] \(81=3^{4}\) \end{solutionordottedlines} \part 128 \begin{solutionordottedlines}[2cm] \(128=2^{7}\) \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] \(2 a^{2} b^{3} \times 5 a b^{2}=10 a^{3} b^{5}\) \end{solutionordottedlines} \part \(\frac{3^{5}}{3^{2}}\) \begin{solutionordottedlines}[2cm] \(\frac{3^{5}}{3^{2}}=3^{3}\) \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] \(10^{6} \div 10^{4}=10^{2}\) \end{solutionordottedlines} \part \(a^{7} \div a^{4}\) \begin{solutionordottedlines}[2cm] \(a^{7} \div a^{4}=a^{3}\) \end{solutionordottedlines} \part \(\frac{3 y^{4}}{y}\) \begin{solutionordottedlines}[2cm] \(\frac{3 y^{4}}{y}=3 y^{3}\) \end{solutionordottedlines} \part \(\frac{6 x^{5}}{2 x^{3}}\) \begin{solutionordottedlines}[2cm] \(\frac{6 x^{5}}{2 x^{3}}=3 x^{2}\) \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] \(\frac{8 a^{2} b^{3}}{3 a^{3} b} \div \frac{4 a b^{2}}{9 a^{3} b^{5}}=\frac{8 a^{2} b^{3}}{3 a^{3} b} \times \frac{9 a^{3} b^{5}}{4 a b^{2}}=6 a b^{5}\) \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] \(\left(\frac{2}{3}\right)^{2}=\frac{2^{2}}{3^{2}}=\frac{4}{9}\) \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] \(\left(\frac{x^{3}}{y^{2}}\right)^{2} \times\left(\frac{y}{x}\right)^{4}=\frac{x^{6}}{y^{4}} \times \frac{y^{4}}{x^{4}}=x^{2}\) \end{solutionordottedlines} \part \(\left(\frac{2 x^{2}}{3}\right)^{2} \div \frac{4 x^{3}}{9}\) \begin{solutionordottedlines}[2cm] \(\left(\frac{2 x^{2}}{3}\right)^{2} \div \frac{4 x^{3}}{9}=\frac{4 x^{4}}{9} \times \frac{9}{4 x^{3}}=x\) \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] \(\frac{6 x^{2} y}{x y^{2}} \times \frac{y^{3} x}{2 y^{2} x^{2}}=3\) \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] \(\left(2 a^{4}\right)^{3}=2^{3} a^{12}=8 a^{12}\) \end{solutionordottedlines} \part \(2\left(x^{2} y\right)^{0} \times\left(x^{2} y^{3}\right)^{3}\) \begin{solutionordottedlines}[2cm] \(2\left(x^{2} y\right)^{0} \times\left(x^{2} y^{3}\right)^{3}=2 x^{6} y^{9}\) \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 \(6^{4}=\fillin[Base: 6, Index: 4]\) \begin{solutionordottedlines}[2cm] \end{solutionordottedlines} \part \(7^{3}=\fillin[Base: 7, Index: 3]\) \begin{solutionordottedlines}[2cm] \end{solutionordottedlines} \part \(8^{2}=\fillin[Base: 8, Index: 2]\) \begin{solutionordottedlines}[2cm] \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}[2cm] \(2^{7} \times 2^{3}=2^{10}\) \end{solutionordottedlines} \part \(3^{3} \times 3^{4} \times 3^{5}\) \begin{solutionordottedlines}[2cm] \(3^{3} \times 3^{4} \times 3^{5}=3^{12}\) \end{solutionordottedlines} \part \(3 x^{2} \times 4 x^{3}\) \begin{solutionordottedlines}[2cm] \(3 x^{2} \times 4 x^{3}=12 x^{5}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[4] Simplify: \begin{parts}\begin{multicols}{2} \part \(a^{2} b^{3} \times b^{2}\) \begin{solutionordottedlines}[2cm] \(a^{2} b^{3} \times b^{2}=a^{2} b^{5}\) \end{solutionordottedlines} \part \(a^{3} b \times a^{2} b^{3}\) \begin{solutionordottedlines}[2cm] \(a^{3} b \times a^{2} b^{3}=a^{5} b^{4}\) \end{solutionordottedlines} \part \(2 x y^{2} \times 3 x^{2} y\) \begin{solutionordottedlines}[2cm] \(2 x y^{2} \times 3 x^{2} y=6 x^{3} y^{3}\) \end{solutionordottedlines} \part \(4 a^{3} b^{2} \times a^{2} b^{4}\) \begin{solutionordottedlines}[2cm] \(4 a^{3} b^{2} \times a^{2} b^{4}=4 a^{5} b^{6}\) \end{solutionordottedlines} \end{multicols}\end{parts} \Question[6]$\,$ \begin{parts}\begin{multicols}{2} \part \(\frac{3^7}{3^2}\) \begin{solutionordottedlines}[2cm] \(\frac{3^7}{3^2}=3^{5}\) \end{solutionordottedlines} \part \(\frac{2^{6}}{2^{2}}\) \begin{solutionordottedlines}[2cm] \(\frac{2^{6}}{2^{2}}=2^{4}\) \end{solutionordottedlines} \part \(10^{7} \div 10^{2}\) \begin{solutionordottedlines}[2cm] \(10^{7} \div 10^{2}=10^{5}\) \end{solutionordottedlines} \part \(\frac{10^{12}}{10^{4}}\) \begin{solutionordottedlines}[2cm] \(\frac{10^{12}}{10^{4}}=10^{8}\) \end{solutionordottedlines} \part \(\frac{2 x^{3}}{x^{2}}\) \begin{solutionordottedlines}[2cm] \(\frac{2 x^{3}}{x^{2}}=2 x\) \end{solutionordottedlines} \part \(\frac{6 x^{5}}{2 x^{2}}\) \begin{solutionordottedlines}[2cm] \(\frac{6 x^{5}}{2 x^{2}}=3 x^{3}\) \end{solution