Question

pls answer this I'll mark him/her as brainliest
simplify by using suitable identity
(20x+ 3) (20x-5)​

Answer 1

Step-by-step explanation:

(20x+ 3) (20x-5)

By using identity (x+a) (x+b)= x²+(a+b)x+ab

(20x+3) (20x-5)= (20x)²+(3-5)20x+3×(-5)

= 400x²+(-2)20x-15

= 400x²-40x-15. ( Factor of 5 )

= 80x²-8x-3

Answer 2

Answer:

$(20x + 3) (20x -5)$

Let us assume it as,  $(x + a)(x - b)$

Where, x = 20x

            a = 3

            b = 5

We know that,

$(x + a)(x - b) = x^2 + (a - b)x - ab$

 ∴ $(20x + 3) (20x -5 )= (20x)^2 + (3 - 5)20x - (3 * 5)$

                                  = $400x^2 - 40x - 15$

                                  = $5(80x^2 - 8x - 3)$

                    Hope it helps you^_^