Question

(x+2)(x-3)(x+5) is identical to x³+ax²-11x+b. Find the value of b.

Answer 1

Answer:

(x+2)(x-3)(x+5)

=(x^2+2x-3x-6)(x+5)

=(x^2-x-6)(x+5)

=x^3-x^2-6x+5x^2-5x-30

=x^3+4x^2-11x-30

as it is identical to

x^3+ax^2-11x+b

so, here a=4 and b= -30