Question

factorise 2x Cube + 7 x square minus 3 x minus 18

Answer 1

2x^3 + 7x^2 - 3x - 18

= 2x^3 + ( 4x^2 + 3x^2) + ( 6x - 9x) - 18

= 2x^3 + 4x^2 +3x^2 + 6x - 9x - 18

= 2x^2 ( x + 2) + 3x ( x + 2) - 9(x +2)

= (x + 2) [ 2x^2 + 3x - 9]

= (x +2) [ 2x^2 + 6x - 3x - 9]

= (x +2) [ 2x ( x + 3) - 3(x + 3)]

= (x +2)(x +3)(2x - 3)

Answer 2

(2x^3+7x^2+3x)-18. (2x^3+6x^2+x^2+3x)-18. 2x^2(x+3)x(x+3)-18. (x+3)(2x^2+x-18). (x+3)(2x^2+36x-x-18). (x+3)2x(x+18)-1(x+18). (x+3)(x+18)(2x-1).