Question

factorise : x³+13x²+32x+20​

Answer 1

Answer:

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

Step-by-step explanation:

x³ + 13x² + 32x + 20

Subsistuting x = -2

-2³ + 13*-2² + 32*-2 + 20

= -8 + 52 - 64 + 20

= 0

Therefore,

(x+2) is one factor

_____________

x+2|x³+13x²+32x+20|x²+11x+10

x³ + 2x²

(-) (-)

------------------------

0 + 11x² + 32x + 20

11x² + 22x

(-) (-)

------------------------

0 + 10x + 20

+ 10x + 20

(-) (-)

----------‐-------------

0 + 0

------------------------

x²+11x+10

=x²+1x+10x+10

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

=(x+1)(x+10)

Therefore,

x³ + 13x² + 32x + 20

=

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