Chapter 9 - Quadratic Functions and Equations - 9-5 Completing the Square - Practice and Problem-Solving Exercises - Page 580: 45

$x=13,-15$

Consider the expression: $x^2+2x-195=0$ or, $x^2+2x=195$ Compare it with the standard form of quadratic equation $ax^2+bx+c$, we have $a=1, b=2$ To complete the square, add $1$ on both sides. $x^2+2x+1=195+1$ $\implies (x+1)^2=196$ $\implies (x+1)=14$ and $\implies (x+1)=-14$ or, $x=13,-15$