# Thread: Solve for the system

1. ## Solve for the system

$x^2 + y^2 = 9,$
$y = x^2 + 4$

I don't know, but do you just substitute in y and solve?

Thanks for the help!^^

2. Put x^2 = y - 4 in the first equation and solve the quadratics for y.

3. oops. my mistake. the equations were:

$

x^2 + y^2 = 9,
$

$

y = 2x -3
$

4. Square the second equation to get: (2x-3)^2. Substitute that into the first equation. Solve for x. Plug the value you found for x back into equation 2, that gives you y.