Answer
$y=1$ if $x\leq -1$
$y=-x +1$ if $-1 \lt x \leq 2$
$y=-2$ if $x\gt 2$
Work Step by Step
For the first one, we can see that there is no slope. Therefore, $y=1$
For the second one, we can see that there is a rise of $-1$ unit and run of $1$ unit. Therefore, its slope $m = {rise\over run} = -1$ The y-intercept $b$ is $1$ as seen on the graph. So, we can use these values to find the standard equation $y=mx+b$ --> $y=-x+1$
For the third one, we can see that there is no slope. Therefore, $y=-2$
