Chapter 9 - Quadratic Functions and Equations - 9-6 The Quadratic Formula and the Discriminant - Practice and Problem-Solving Exercises - Page 586: 7

$x=-1$ $x=-\dfrac{3}{2}$

$x=\dfrac{-b±{\sqrt {b^{2}-4ac}}}{2a}$ and $2x^{2}+5x+3=0$.Therefore, $a=2$,$b=2$ and $c=3$: Substitute the values: $x=\dfrac{-5±{\sqrt {4^{2}-4(2)(3)}}}{2(2)}$ =$\dfrac{-5±{\sqrt {25-24}}}{4}$ =$\dfrac{-5±1}{4}$ Separate the equation into plus and minus equations: $x=\dfrac{-5+1}{4}=-1$ $x=\dfrac{-5-1}{4}={\dfrac{-3}{2}}$