Question 291017
{{{x^2+7=7}}} Start with the given equation.



{{{x^2+cross(7-7)=7-7}}} Subtract 7 from both sides.



{{{x^2=0}}} Combine like terms.



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



{{{x=sqrt(0)}}} or {{{x=-sqrt(0)}}} Break up the "plus/minus" to form two equations.



{{{x=0}}} or {{{x=-0}}} Take the square root of zero to get zero.



Because negative zero is really zero, this means that there is only one solution which is {{{x=0}}}.