Question

x^2+4y=100
4y-x^2=-20
How in the world so I solve this system of equations please help fast!
Do I use substitution? I don't clearly see how I would solve for x or y in either equation.

Answer 1

you can use substitution because x^2 on the first equation is positive and negative on the second equation. They will cancel out

Answer 2

*as i was, the 4y's will cancel out

Answer 3

so add them together

Answer 4

I get y=10

Answer 5

yup x^2-(-x^2)=2x^2 and then 100-(-20)=120 2x^2=120 120/2=60 x^2=60 and then take the square root

Answer 6

yeah so square root of 60 = x

Answer 7

exactly, and whatever x equals you plug it into to one of the equations to find y

Answer 8

I plugged it into the second equation and it worked. So does that mean there is only one solution?

Answer 9

no the number you plugged in is the answer for x. The answer you got after you plugged it in is y

Answer 10

remember, there is an x and a y so there has to be at least 2 answers, one for each letter

Answer 11

Yeah so (sqrt60, 10) is the only solution?

Answer 12

I got the answer wrong it was actually (6,4) :(((