Question

4a2-9b2 evaluate using identity

Answer 1

(2a-3b) (2a+3b) will answer by using the identity a^2-b^2

Answer 2

Heya!!
Here is the answer:
We have to evaluate i.e factorise 4a^2-9b^2 by a suitable alegbraic identity.
=>Solution:
$4 {a}^{2} - 9 {b}^{2}$
This can also be written as :-
${(2a)}^{2} - {(3b)}^{2} (i)$
We know the identity:-
${a}^{2} - {b}^{2} = (a + b)(a - b)$
We can see that ( i ) fits in this identity.
So here :-
$a = 2a$
and,
$b = 3b$
So substituting these values of a and b in that identity, we get:-
${(2a)}^{2} - {(3b)}^{2} =( 2a + 3b)(2a - 3b)$
So , we have factorise it.

Hope it helps you.