Question 114336
I presume you want to solve {{{5x^2=100}}} for x.


Step 1:  Divide by 5


{{{x^2=20}}}


Step 2:  Take the square root of both sides, remembering to consider both the positive and negative square root.


{{{sqrt(x^2)=sqrt(20)}}} and {{{sqrt(x^2)=-sqrt(20)}}}



{{{x=2sqrt(5)}}} and {{{x=-2sqrt(5)}}}