Question 1066869
Again?
??


{{{x^2+(x+5)^2=200}}}
SOLVE FOR x.  If you do it well, you should trust your efforts & your work.  


{{{x^2+x^2+10x+25=200}}}


{{{2x^2+10x+25=200}}}


{{{2x^2+10x-175=0}}}


Maybe factorable or maybe not.  Use general solution to quadratic equation if you want to avoid trying to factorize.


Discriminant:  {{{10^2-4*2*(-175)=100+8*175=1500}}}


You want the PLUS form for x.
{{{x=(-10+sqrt(1500))/4}}}


{{{x=(-10+10sqrt(15))/4}}}


{{{highlight(x=(-5+5*sqrt(15))/2)}}}