slope of the line passing through the points (-1,-3) and (2,5)
First you're going to want to find the slope of the line passing through these two points:
Y2 - Y1 5 - (-3) 8
slope = m = ---------- then plug in your numbers: --------- = ----
X2 - X1 2 - (-1) 3
Then you need to use the point slope form to figure out the equation.
Y - Y1 = m(X - X1) then plug in your numbers:
Y - (-3) = 8/3(X - (-1))
Y = 8/3X + 8/3 - 3
Y = 8/3X + 8/3 - 9/3 (common denominator to subtract 3 from 8/3)
Y = 8/3X - 1/3 (This is your straight line equation)