Question 765635
x^2+y^2=4
x^2-y^2=1

add the two equations

2x^2=5
/2
x^2=5/2

x= +/- (5/2)

plug x=(5/2) in the first equations
(5/2)^2+y^2=4

25/4  +y^2=4
y^2=4-(25/4)

y^2=-(9/4)

y=(3/2)I
x=(5/2) , y= (3/2)i