100 Points for two questions will give brainliest (MUST SHOW WORK)

Answer:
21. (-1,-15)
22. (-12,3)
Step-by-step explanation:
(-5,-1) and (-3,-8)
-3--5 to get 2.
-8--1 to get -7
-7/2=-3.5
On a graph, plot both points and draw a line with a slope of -3.5 through both of them. Next, count down 7 and then count two to the right. Then you will land on a point. That point is the other endpoint. Making the answer (-1,-15)
(6,-5) and (-3,-1)
-1--5 to get 4.
-3-6 to get -9.
-4/9 is the slope of the line.
On a graph, plot both points and draw a line with a slope of -4/9 through both of them. Next, count up 4 and then count nine to the left. Then you will land on a point. That point is the other endpoint. Making the answer (-12,3)