What are the solutions to the equation f(x)=g(x)?

If   f(x) = g(x)    Just set them equal

 

7      =      x^2+2x -8       subtract 7 from both sides

0 = x^2 + 2x - 15             now either factor  in your head....or use the quadratic formula     a = 1 b = 2  c = -15

\(x = {-b \pm \sqrt{b^2-4ac} \over 2a}\) 

 

(x+5)(x-3) = 0       so x = -5   or 3