Answer:The roots are 3 and -6
Step-by-step explanation:The general formula of the quadratic equation is:
ax²+ bx + c = 0
The given equation is:
x² + 3x - 18 = 0
By comparison, we can find that:
a = 1
b = 3
c = -18
To get the roots, we will use the quadratic formula shown in the attached image.
By substituting in the equation, we would find that:
either x =

or x =

This means that the roots are: 3 and -6
Hope this helps :)