Answer
x=-5
and
x=1
Step-by-step explanation
The equation y = 2(x+2)^2 - 18 corresponds to a translation 2 units left and 18 units down, and a and a shrinkage about the x-axis with factor 2.
Making these transformations to y=x^2, we have:
Factoring:
The x-intercept are found when y=0, that is:
and