text: ## Elementary and Intermediate Algebra: Concepts & Applications (6th Edition)
  
  $\displaystyle \{-\frac{3}{4},\frac{5}{6}\}$
  ...subtract 15 $24x^{2}-2x-15=0$ ... factoring, we seek factors of $ac=-360$ whose sum is $b=-2$ ... we find +18 and -20 $24x^{2}-20x+18x-15=0$ $4x(6x-5)+3(6x-5)=0$ $(6x-5)(4x+3)=0$ $6x-5=0\displaystyle \quad\Rightarrow\quad x=\frac{5}{6}$ $4x+3=0\displaystyle \quad\Rightarrow\quad x=-\frac{3}{4}$ Solution set = $\displaystyle \{-\frac{3}{4},\frac{5}{6}\}$