Question

Find the intercepts if any

x^2+y^2+8x-8y-49=0

EW1

Answer 1

at the x-intercepts, y = 0 , so ...

x^2 + 0 + 8x - 0 - 49=0

using completing the square:
x^2 + 8x +16 = 49+16
(x+4)^2 = 65
x+4 = ±√65
x = -4 ± √65
or appr 4.06 or appr -12.06

confirmation. Notice your equation represents a circle

http://www.wolframalpha.com/input/?i=x%5E2%2By%5E2%2B8x-8y-49%3D0