Question

Factorise 8+6(a+b)-5(a+b)^2

Answer 1

By factorisation we get => 2( 4 + 3a + 3b – 15a^2 – 30ab – 15b^2 )
Hope this answer helps you......

Answer 2

Here  - 5( a + b)² + 6 (a + b) + 8

Let ( a + b) = x

Putting it in given equation, we get

- 5x² + 6x + 8

To factorise it, we have to multiply constant term with coefficient of x²

-5 × 8 = -40

Now, find two numbers such that their product is -40 and sum or difference is 6, in this case -4 × 10 = -40 and -4 + 10 = 6, so lets split coefficient of x

-5x² + 10x - 4x + 8

Taking -5x common from first two terms and -4 from last two terms

-5x ( x - 2) -4 (x - 2)

(x - 2) (-5x - 4)

Putting value of x = a + b

(a + b -2) [ -5(a + b) -4]

(a + b -2) (-5a -5b -4) or

- (5a + 5b + 4) (a + b -2)