factorise : x³+13x²+32x+20
Answers
Answered by
50
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)
Similar questions