Question

using the suitable identity find (2a+3b) (2a-b)​

Answer 1

Answer:

by using (x+a)(x+b)=x^2+(a+b)x +ab

we get

(2a)^2 +(3b-b)(2a)+3b(-b)

4a^2 +4ab-3b^2

Answer 2

Answer:

$\: \: using \: \: this \: \: identity \: \\ (x + a )(x + b) = {x}^{2} + x(a + b) + ab \\ (2a + 3b)(2a - b) = (2a {)}^{2} + 2a(3b + ( - b)) + 3b \times ( - b) \\ = 4 {a}^{2} + 2a(3b - b) + ( - 3 {b}^{2} ) \\ = 4 {a}^{2} + 2a \times 2b - 3 {b}^{2} \\ = 4 {a}^{2} + 4ab - 3 {b}^{2}$

I hope it will help you