Chapter 9 - Quadratic Functions and Equations - 9-7 Linear, Quadratic, and Exponential Models - Mixed Review - Page 580: 33

$x= 1.8235, -3.8285$

$x^2+2x-7=0$ $x=(-b±\sqrt {b^2-4ac})/2a$ $x=(-2±\sqrt {2^2-4*1*-7})/2*1$ $x=(-2±\sqrt {4+28})/2$ $x=(-2±\sqrt {32})/2$ $x=(-2±5.657)/2$ $x=(-2+5.657)/2$ $x=3.657/2 = 1.8235$ $x=(-2-5.657)/2$ $x= -7.657/2 = -3.8285$