Question

Factorise the following expressions using suitable identity 20x^2-45

Answer 1

Step-by-step explanation:

$20 {x}^{2} - 45 \\ = 5(4 {x}^{2} - 9) \\ = 5(2x + 3)(2x - 3)$

This is done using the algebraic identity:

a²-b² = (a+b)(a-b)

Answer 2

Answer:

5(2x+3)(2x−3)

Step-by-step explanation:

20x^2−45

5(4x^2−9)

5(2x+3)(2x−3) [a^2 - b^2 = (a+b)(a-b)]