Question

7. Factorise (i) x3 – 2x² - x + 2
(iii) x3+ 13x² + 32x + 20
(ii) x3– 3x2 - 9x - 5
(iv) y3 + y2-y-1​

Answer 1

The value of x3+13x²+32x+20 is

x 3 +x² +12x² +12x+20x+20

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

=(x−1)(x²+12x+20)

=(x−1)(x²+10x+2x+20)

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

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