To find the roots of a polynomial function, set the polynomial equal to zero and solve for x.
x² + 10x - 96 = 0
We need to factor the left side. The left side is a quadratic polynomial whose first coefficient is 1. We need two numbers whose product is -96 and whose sum is 10. The numbers are 16 and -6.
(x + 16)(x - 6) = 0
If a product of two factors equals zero, then one factor or the other or both must equal zero.