Question

Question 1(vii)
Use a suitable identity to get each of the following products:
$(6x-7)(6x+7)$

Answer 1

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

Using the identity $\left(a+b\right)\left(a-b\right)=a^2-b^2$ where $a=6x\:\text{and}\:b=7$

$=36x^2-49$

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