How do you find the exact solutions to the system y^2=x^2-7y2=x27 and x^2+y^2=25x2+y2=25?

1 Answer
Oct 7, 2016

Let equation 1 be y^2 = x^2 - 7y2=x27 and equation 22 be x^2 + y^2 = 25x2+y2=25.

We know the value of y^2y2 in both equations, so we can substitute y^2y2 in equation 11, which is already isolated, for y^2y2 in equation 22.

x^2 + (x^2 - 7) = 25x2+(x27)=25

2x^2 = 322x2=32

x^2 = 16x2=16

x = +- 4x=±4

y^2 = 4^2 - 7" AND "y^2 = -4^2 - 7y2=427 AND y2=427

y^2 = 9" AND "y^2 = 9y2=9 AND y2=9

y = +-(3)" AND "y = +-(3)y=±(3) AND y=±(3)

:.The solution is (+-4, +-3)

Hopefully this helps!