Answer 1

By remainder theorem we know that when a polynomial f (x) is divided by x – a, then the remainder is f(a) 

let `f(x)=2x^3+3x^2-5x-6` 

`f(-1)=2(-1)^3+3(-1)^2-5(-1)-6=-2+3+5=0` 

Thus, (x + 1) is a factor of the polynomial f(x).