<PRE><B>Question 806048</B>
x^2+y^2=17 
x+y=5

x^2+y^2+2xy-2xy  =17 

(x+y)^2-2xy =17

5^2-2xy=17
2xy=25-17
2xy=8
xy=4
y=4/x

x+(4/x)=5

x^2+4=5x
x^2-5x+4=0
x^2-4x-x+4=0
x(x-4)-1(x-4)=0
(x-4)(x-1)=0
x=4 OR 1

plug x to get y

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