Question

1) {x^2+y^2=-21
     x+y=-3
2) {x^2+4y^2=34
    x+y=7   
reshite sistemu uravneniy

Answer 1

{x^2+y^2=-21
x=-y-3
(-y-3)^2+y^2=-21
-(y+3)^2+y^2=-21
-(y^2-6y+9)+y^2=-21
-y^2+6y-9+y^2=-21
6Y=21+9
6y=30
x=5

{x^2+4y^2=34
x=7-y
(7-y)^2+4y^2=34
49-14y+y^2+4y^2=34
5y^2-14y+15=0
D=16
x1=2.4
x2=1