I think the answer would be Y = -1/2x + 6
First we would do 5-7/2 - (-2), and would get -2/4. Which could get simplified to -1/2
Then we would have to find the Y intercept/B, by in putting the slope and Y and X coordinates.
For example, 7 = -1/2 (-2) + b
7 = 2/2 + B
7 - 1 = B.
Then we could form an equation.
Y = -1/2x + 6.