Please help with this question

Answer:
The roots (or, solutions or zeroes) to the polynomial are:
x = 0, 3, -6, 7
Step-by-step explanation:
If (x - a) is a factor of the polynomial then x = a is definitely a root of the polynomial. The converse is also true.
Here, we have 4 factors. So, a polynomial of degree 4 and hence have 4 roots.
x is the first factor.
⇒ x = 0 is a root to the polynomial.
We see (x - 3) is another factor.
⇒ x = 3 should be another root of the polynomial.
Now, (x + 6) is another factor to the polynomial.
So, x = - 6 should be a zero to the polynomial.
Finally, if (x - 7) is a factor of the polynomial then x = 7 should be a zero to it.
So, we have 4 roots, viz., 0, 3, -6, 7 as zeroes to the polynomial.