Question

What are the x-coordinates of the solutions to this system of equations?

x2 + y2 = 16
y = x + 4

A.) -4 and 0

B.)4 and 0

C.) -2 and -3

D.) 2 and -3

Answer 1

@wio

Answer 2

Did you try replacing y in the first equation with x+4?

Answer 3

Im not sure if I did it correctly but I got B @myininaya

Answer 4

If you think it is B, you can check it by pluging your answer into the equations given.
If both equations are satisfied then you did good.

Answer 5

Well first you would need to find y though for both x's

Answer 6

You can use that bottom equation.
It is the most easiest.

Answer 7

You don't need to actually solve the equation. In this question you can just substitute in the answers for \(x\) and see which answer is consistent.

Answer 8

So you have x=4 or x=0
If x=4, then y=4+4=8 (Plug in (4,8))
If x=0, then y=0+4=4 (Plug in (0,4))

Answer 9

I re-did it and got A as my answer

Answer 10

Cool stuff.
That answer is actually correct.

Answer 11

thank you guys @myininaya @wio !