You have the following function:
f(x) = x² + x - 12
In order to find the roots of the previous function, use the quadratic formula:
take into account that the general for of a quadratic function is:
f(x) = ax² + bx + c
by comparing the previous function with the given function of the question you have:
a = 1, b = 1, c = -12
repalce these values into the quadratic formula:
from the previous expressio for x, you obtain two solutions:
x = (-1-7)/2 = -8/2 = -4
x = (-1+7)/2 = 6/2 = 3
Hence, the roots of the given function are -4 and 3. And Scott is wrong