PLEASE HELP ME I WILL MARK U AS THE BRAINIEST ANSWER!

(21, 8)

(3, 2)

(-15, -4)

Step-by-step explanation:

First we need to create the equation in y=mx +b form.

(m) is slope [rise/run]

(b) is y intercept

The line crosses the y axis at (0,1) so that's our (b) and to find slope we will find a point where ethe line crosses a point, I'll use (0, 1) and see how many it has to go to reach the next point. In this case it has to go up 1, and right 3.

Our slope is 1/3.

y=1/3x+1.

Now we can start applying the given points.

(21, 8)

8=1/3(21)+1

8=7+1

8=8.

(21, 8) is a solution.

(3, 2)

2=1/3(3)+1

2=1+1

2=2

(3, 2) is a solution.

(-15, -4)

-4=1/3(-15)+1

-4=-5+1

-4=-4

(-15, -4) is a solution.

(12, 9)

9=1/3(12)+1

9=4+1

9=5

(12, 9) is not a solution.

(-6, 1)

1=1/3(-6)+1

1=-2+1

1=-1

(-6, 1) is not a solution.

Hope this helps! If you have any questions on how I got my answer feel free to ask. Stay safe!

answer: add the !

step-by-step explanation: then we will answer