Question 132986
{{{2x^2 - 3 = 15}}} Start with the given equation



{{{2x^2 +cross(- 3+3) = 15+3}}} Add 3 to both sides



{{{2x^2= 18}}} Combine like terms



{{{cross(2/2)x^2= 18/2}}} Divide both sides by 2



{{{x^2= 9}}} Reduce



{{{x=0+-sqrt(9)}}} Take the square root of both sides



Break up the expression


{{{x=sqrt(9)}}} or {{{x=-sqrt(9)}}}



Take the square root of 9 to get 3


{{{x=3}}} or {{{x=-3}}}



So our answer is 



{{{x=3}}} or {{{x=-3}}}