Question 183505
x^2+(x-7)^2=13^2
x^2+x^2-14x+49=169
2x^2-14x+49-169=0
2x^2-14x-120=0
2(x^2-7x-60)=0
2(x-12)(x+5)=0
x-12=0
x=12 ans.
12-7=5 ans.
Proof:
12^2=5^2=13^2
144+25=169
169=169