Question 163403
x^2+y^2=20
2x+2y=56
2x=56-2y
x=(56-2y)/2
x=28-y
(28-y)^2+y^2=20^2
784-56y+y^2+y^2=400
2y^2-56y+784-400=0
2y^2-56y+384=0
2(y^2-28y+192)=0
2(y-16)(y-12)=0
y-16=0
y=16 Answer. Then x=12.
y-12=0
y=12 Answer. Then x=16.
Proofs:
2*16+2*12=56
32+24=56
56=56
16^2=1262=20^2
256+144=400
400=400