Question

Solve :
x^2-y=7
x^2+y^2= 49

Answer 1

Try multiplying one equation by -1, then adding the two equations.

Answer 2

ok

Answer 3

so it be -x^2+y=-7?

Answer 4

Yes. Now add that to the second equation. What do you get?

Answer 5

y+y^2=42?

Answer 6

Yes! Now this is just a quadratic equation. Get all terms on one side and solve it. What do you get?

Answer 7

y^2+y=-42

Answer 8

How did that 42 get negative?
The answer is y^2 + y - 42 = 0. Now solve it. What do you get?

Answer 9

positive 42 lol my bad

Answer 10

(y+7) (y-6)?

Answer 11

Good. Now you know how to solve that.

Answer 12

thats it?

Answer 13

Indeed it is. Don't forget to plug your value of y in to one of the original equations to get x when you're done! Good work. A medal's coming your way. :)

Answer 14

thanks! but which solution do i use? both? so i have 2 different ordered pairs?