Answer:
You have to find the slope first. Which is y1-y1 divided by x1-x2
Then you find the y-intercept which you take the slope for m like for example if you find the slope, 2, then the equation should be y=2x+b. You take the coordinates on the problem and put them on the y or x on the equation. Then when you find the y-intercept you add it to the equation like for the example that I used above, you have to put the y-intercept on b. So if the y-intercept is 5 then the equation would be y=2x+5.