Answer:
Step-by-step explanation:
The best way to do this is to set the quadratic = to 0 and solve for x.
[tex]2x^2-18=0[/tex] and
[tex]2x^2=18[/tex]
Divide both sides by 2:
[tex]x^2=9[/tex] and then take the square root of both sides, which will give you both the positive AND the negative number of the square root of 9.
x = 3, -3
