Chapter 3 - Polynomial and Rational Functions - Section 3.2 The Real Zeros of a Polynomial Function - 3.2 Assess Your Understanding - Page 225: 114

$-3$.

Step 1. Use synthetic division as shown in the figure to get the quotient. Step 2. Find other zeros $x^2+3x-1=0 \Longrightarrow x=\frac{-3\pm\sqrt {9+4}}{2}=\frac{-3\pm\sqrt {13}}{2}$ Step 3. Thus the sum of the remaining solutions is $-3$.