Question 900760
x^2+(x+7)^2=13^2
x^2+(x+7)(x+7)=169
x^2+x^2+14x+49=169
2x^2+14x=120
2x^2+14x-120=0
x^2+7x-60=0

*[invoke change_this_name4450 1, 7, -60, "x"]
x+12=0
 x=-12  reject negative distance
x-5=0
x=5 miles
x+7=12 miles
The famous 5,12,13 right triangle
BTW The other tutor entered -6 instead of -60 into the solver