Question

Factorise x3 + 2x2 - 9x – 18.

Answer 1

ANSWER

x2(x+2)−9(x+2)

(x+2)(x^2−3^2)

(x+2)(x+3)(x−3)

Answer 2

p(X)=x³+2x²-9x-18

then for X=-2

=(-2)³+2(-2)²-9(-2)-18

=-8+8+18-18=0

thus (X+2) is a factor of p(X)

then by long dinision

x³+2x²-9x-18/X+2

and it and. should b 0

then by division algorithm and middle term splitting,

u will get the factors

hope u will understand