Question 1088139
{{{x^2+(x-7)^2=13^2}}}
{{{x^2+x^2-14x+49=169}}}
{{{2x^2-14x-120=0}}}
{{{x^2-7x-60=0}}}
{{{(x-12)(x+5)=0}}}
Only positive values for x make sense here,
{{{x-12=0}}}
{{{x=12}}}
{{{x-7=5}}}
5-12-13 triangle.