大象传媒

Laws of indices - EdexcelMultiplying indices

Indices are used to show numbers that have been multiplied by themselves. They can be used instead of the roots such as the square root. The rules make complex calculations that involve powers easier.

Part of MathsNumber

Multiplying indices

Example

\(c^3 \times c^2\).

To answer this question, write \(c^3\) and \(c^2\) out in full: \(c^3 = c \times c \times c\) and \(c^2 = c \times c\).

\(\mathbf{c^3} \times c^2 = \mathbf{c \times c \times c} \times c \times c\). Writing the indices out in full shows that \(c^3 \times c^2\) means \(c\) has now been multiplied by itself 5 times. This means \(c^3 \times c^2\) can be simplified to \(c^5\).

However, \(d^3 \times e^2\) cannot be simplified because \(d\) and \(e\) are different.