Exercise 12 Page 348

We can check our answer by substituting the given zeros for $x.$ If the result is $y=0,$ it means that the given numbers are actually zeros of the function and our answer is correct. Let's start by checking $\text{-}1.$ We proved that $\text{-}1$ is a zero of the function. Let's now check $6.$ We found that $6$ is also a zero. Since $\text{-}1$ and $6$ are zeros of the polynomial function, our answer is correct.