Question

Factorise : (x2 – 3x)2 – 8(x2 – 3x) - 20.​

Answer 1

Answer:

(x^2-3x)-8(x^2-3x)-20

let( x^2-3x)=y

then ,

y^2-8y-20

=y^2-10y+2y-20

=y(y-10)+2(y-10)

=(y-10)(y+2)

putting the value of y

(x^2-3x-10)(x^2-3x+2)

(x^2-5x+2x-10)(x^2-2x-x+2)

={x(x-5)+2(x-5)}{x(x-2)-1(x-2).}

=(x-5)(x+2)(x-2)(x-1)