Question

Using distributive law, find the square of $72$.

Answer 1

Finding the square of $72$ by using distributive law

On applying the distributive law,

we know that $72$ can be expressed as

$72=70+2$

So,

$$\begin{gathered} {72}^2={(70+2)}^2 \\ =(70+2)(70+2) \\ =70(70+2)+2(70+2) \\ =\left(\right(70\times 70)+(70\times 2\left)\right)+\left(\right(2\times 70)+(2\times 2\left)\right) \\ =4900+140+140+4 \\ =5184 \end{gathered}$$

The square of the given number i.e. ${72}^2=5184$