Chapter 5 - Linear Functions - 5-3 Slope-Intercept Form - Practice and Problem-Solving Exercises - Page 310: 21

$y=-2x+\frac{8}{5}$

The slope-intercept form of a linear equation of a non vertical line is $y=mx+b$, where $m$ is the slope and $b$ is the $y$-intercept. We plug in $m=-2$ and $b=\frac{8}{5}$ to this equation to get $y=-2x+\frac{8}{5}$