Question

x^2-14x-49=0

Answer 1

Are you sure it is -49?

Answer 2

It seems like (x-7)^2 = x^2 - 14x + 49 = 0
=> x = 7.

Could be that it is indeed -49. In that case, you get roots using quadratic formula.

(14 +/- SQRT(196 + 196))/2
=> (14 +/- 14*SQRT(2))/2
=> 7 (1+SQRT(2)) OR 7(1-SQRT(2))