Question 967820
X^2+y^2=25
X^2=25-Y^2

X+y=7
X=7-Y
(7-Y)^2=25-Y^2
49-14Y+Y^2=25-Y^2
49-25-14Y+Y^2+Y^2=0
2Y^2-14Y+24=0
2(Y^2-7Y+12)=0
Y^2-7Y+12=0
(Y-4)(Y-3)=0
Y-4=0
Y=4 ANS.
Y-3=0
Y=3 ANS
IF Y=4 THEN
X+4=7
X=7-4
X=3 
IF Y=3 THEN
X+3=7
X=7-3
X=4
PROOF:
3^2+4^2=25
9+16=25
25=25