Question

Use a suitable identity to get each of the following products.

$\left(6x-7\right)\left(6x+7\right)$

Answer 1

Solving $\left(6x-7\right)\left(6x+7\right)$,

We will use the identity $\left(a-b\right)\left(a+b\right)=a^2-b^2$

So,

$$\begin{gathered} \left(6x-7\right)\left(6x+7\right)={\left(6x\right)}^2-7^2 \\ \left(6x-7\right)\left(6x+7\right)=36x^2-49 \end{gathered}$$

Hence, $\left(6x-7\right)\left(6x+7\right)=36x^2-49$