Chapter 4 - Quadratic Functions - 4.5 Solving Equations by Factoring - 4.5 Exercises - Page 360: 44

$\left\{-4, 4\right\}$

Write the equation in the form $ax^2+bx+c=0$ to obtain: \begin{align*} x^2-3x+8-24+3x&=0\\ x^2-16&=0\\ (x-5)(x+4)&=0\end{align*} Use the Zero-Product Property by equating each factor to zero, then solving each equation to obtain: \begin{align*} x-4&=0 &\text{or}& &x+4=0\\ x&=4 &\text{or}& &x=-4\\ \end{align*}