ý

Law of indices – division

Example

\(b^5 \div b^3\).

\(b^5 \div b^3\) can be written as \(\frac{b^5}{b^3}\)

\(b^5 \div b^3\)

\(b^5 = b \times b \times b \times b \times b \) and \(b^3 = b \times b \times b\)

\(b^5 \div b^3\) so \(\frac{b^5}{b^3} = \frac{b \times b \times b \times b \times b}{b \times b \times b}\)

There are common factors of b in the numerator and denominator and these can be cancelled out, giving \(\frac{\cancel{b} \times \cancel{b} \times \cancel{b} \times b \times b}{\cancel{b} \times \cancel{b} \times \cancel{b}}\) which leaves \(b \times b = b^2\).

This means \(b^5 \div b^3\) can be simplified to \(b^2\).