Question

Find the product mentally.

Answer 1

(ab+3)(ab−3)

=(ab+3)(ab+−3)

=(ab)(ab)+(ab)(−3)+(3)(ab)+(3)(−3)

=a^2b^2−3ab+3ab−9

=a^2b^2−9

Answer 2

Answer:

Option (c) is correct.

$\left(ab\:+\:3\right)\left(ab\:-\:3\right)=a^2b^2-9$

Step-by-step explanation:

Given : $\left(ab\:+\:3\right)\left(ab\:-\:3\right)$

We have to find the product of $\left(ab\:+\:3\right)\left(ab\:-\:3\right)$

Consider the given expression $\left(ab\:+\:3\right)\left(ab\:-\:3\right)$

Apply algebraic identity, $\left(a+b\right)\left(a-b\right)=a^2-b^2$

We have,

a = ab and b = 3

$=\left(ab\right)^2-3^2$

Simplify, we have,

$=a^2b^2-9$

Thus, $\left(ab\:+\:3\right)\left(ab\:-\:3\right)=a^2b^2-9$