#### Answer

point-slope form: $y-1=3(x-2)$ or $y+8=3(x+1)$
slope-intercept form: $y=3x-5$

#### Work Step by Step

Step 1. Given the two points on the line as $(2,1)$ and $(-1,-8)$, we can calculate the slope as $m=\frac{1+8}{2+1}=3$
Step 2. We can write the line equation in point-slope form as $y-1=3(x-2)$ or $y+8=3(x+1)$
Step 3. We can rewrite the above equations in slope-intercept form as $y=3x-5$