Question

12(x^2+7)^2-8(x^2+7)(2x-1)-15(2x-1)^2 factorise

Answer 1

Answer:

(2x^2-6x + 17) (6x^2+10x+37)

Step-by-step explanation:

Putting x^2+7=u and 2x -1 = v in first we get

12u^2- 8uv- 15v^2= 12u^2 - 18uv+ 10uv- 15v^2

= 6u(2u-3v)+5v(2u - 3v) = (2u - 3v) (6u+5v)

= [2(x^2+7/- 3(2x-1)] [6(x^2+7) + 5(2x - 1)

{Replacing value of u and v}

=(2x^2 + 14 - 6x + 3) (6x^2 + 42 + 10x - 5)

(2x^2-6x + 17) (6x^2+10x+37)