Question 73992
x^2+(x+3)^2=15^2
x^2+x^2+6x+9=225
2x^2+6x+9-225=0
2x^2+6x-216=0
x^2+3x-108=0
(x-9)(x+12)=0
x-9=0
x=9 answer for side 1.
x+12=0
x=-12 not an answer.
9+3=12 is the answer for side 2.
proof
9^2+12^2=225
81+144=225
225=225