Question

Factorise :
(1) r - 2x2 - x + 2
(ii) x + 13x2 + 32x + 20
(i) x - 3x2 - 9x - 5
(iv) 2y3 + y2 – 2y - 1​

Answer 1

Answer:

(ii)

Step-by-step explanation:

The value of x3+13x2+32x+20 is

x 3+x 2+12x 2+12x+20x+20

=x 2(x+1)+12x(x+1)+20(x+1)

=(x−1)(x 2+12x+20)

=(x−1)(x 2+10x+2x+20)

=(x+1)[x(x+10)+2(x+10)]

=(x+1)(x+2)(x+10)

(iii)

X³ - 3x² - 9x - 5

= x³ + x² - 4x² - 4x - 5x - 5

= x²( x + 1) - 4x ( x + 1) - 5(x + 1)

= (x + 1)(x² - 4x - 5)

= (x + 1)(x² -5x + x - 5)

= (x + 1)(x - 5) (x + 1)