Question

Two zeroes of cubic polynomial ax^3 + 3x^2 - bx - 6 are -1 and -2 . Find the third zero and value of a and b

Answer 1

as they are zeroes
then polynomial will be zero at that points

-a+3+b-6 = 0
a-b = -3

-8a+12+2b-6 = 0
4a-b = 3

by the above equations
a = 2 b = 5

polynomial is
2x³+3x²-5x-6
= (x+1)(2x²+x-6)
= (x+1)(x+2)(2x-3)

the third zero is 3/2

hope it helps you
@di