Question

(x+5)(x-4)(x+2) is identical to x^3+ax^2

Answer 1

a = 3

Explanation:

Factorize (x+5)(x-4)(x+2)

(x+5)(x-4)(x+2)

= (x²-4x+5x-20)(x+2)

= (x²+x-20)(x+2)

= (x³+2x²+x²+2x-20x-40)

= x³+3x²-18x -40

Compare with x^3+ax^2

3x² = ax²

3 = a

Rearrange

a = 3

Hence the value of a that makes the expressions identical is 3