Question

factorise (5a +3b)² - 3(5a +3b) -28​

Answer 1

Solution:-

factors >>> (5a+3b-7)(5a+3b+4)

Expln:-

f(5a+3b) = (5a +3b)² - 3(5a +3b) -28

Let x = 5a+3b -- (1)

f(x) = x²-3x-28

By middle term splitting,

f(x) = x²-7x+4x-28

= x(x-7)+4(x-7)

= (x-7)(x+4)

By(1),

factors are (5a+3b-7)(5a+3b+4)