Question

Evaluate using suitable Identities.

1. (2a + 7) (2a – 7)​

Answer 1

Answer:

(a+b).(a-b)=a^2-b^2

Step-by-step explanation:

(2a+7).(2a-7)

=(2a)^2-(7)^2

=4a^2-49

Answer 2

$(2a + 7)(2a - 7)$

The above expression is similar to the identity *$(a + b)(a - b) = {a}^{2} - {b}^{2}$

where $a= 2a$ and $b=7$

And so we have,

$= ( {2a})^{2} - ( {7})^{2}$

$= 4 {a}^{2} - 49$

HAPPY LEARNING!