Question

Solve the following system.

x ^2 + y ^2 = 20
y = x ^2



{(4, -2),(4, 2)}

{(-2, 4), (2, 4)}

(2, 4)

(3, 9)

Answer 1

substitute x^2 =y in first equation. What do you get ?

Answer 2

the answer i got was 2,4

Answer 3

(2,4) is absolutely correct. You just missed a root when you took square root on both sides.
Note that if a = b^2 , then b = sqrt(a) and -sqrt(a).
Now see if you can use this information to find the other root as well.