Question 247102
c=a+8
b=a+7
a^2+b^2=c^2
a^2+(a+7)^2=(a+8)^2
a^2+a^2+14a+49=a^2+16a+64
2a^2-a^2+14a-16a+49-64=0
a^2-2a-15=0
(a-5)(a+3)=0
a-5=0
a=5 ans. 
b=5+7=12 ans. 
c=5+8=13 ans.
Proof:
5^2+12^2=13^2
25+144=169
169=169