Question 978045
The roots for {{{ y=x^2+5x-7}}} are 
{{{x=(-5-sqrt(53))/2}}}  and  {{{x=(-5+sqrt(53))/2}}}.



The rest of the solution to the question is several arithmetic steps.


{{{(-5/2-sqrt(53)/2+(-5/2)+sqrt(53)/2)^2-4((-5-sqrt(53))/2)((-5+sqrt(53))/2)}}}


{{{(-5)^2-(-5-sqrt(53))(-5+sqrt(53))}}}, and recognize the formula for difference of squares.


{{{25-((-5)^2-(53))}}}


{{{25-25+53}}}


{{{highlight(53)}}}