Question

factorise 20a^2-45b^2

Answer 1

Here is your Answer,

By Using identity ,

a²-b²= ( a+b)(a-b)

Given , = 20a²-45b²

It can be written as ,
= (2√5a)²-(3√5b)²

Here a= (2√5a)
b= (3√5b)

= (2√5a - 3√5b)(2√5a +3√5b)

Hope this helps you....✌^_^

Answer 2

20a²-45b²
=5(4a²-9b²)
=5[(2a)²-(3b)²]
=5(2a+3b)(2a-3b)
ANS:- 5(2a+3b)(2a-3b)