So, it is run 2 rise 6. We can fact-check that with 1 to 3 to 5 and 1 to 7 to 13. So, the slope is 3 because of rise over run. So, we can make an equation with y = mx + b. m = 3 because that is the slope. 1=3(1) + b. b=-2. So, the equation is y=3x-2. We can find any x using y and vice versa if we find the equation.
