posted by Jon on .
Write an equation in slope-intercept form for the line that passes through (3,5) and (-2,1).
y= -4/-5x+4.4 (answer)
Rewrite the slope as m = 4/5. -4/-5 is the same thing but looks awkward.
y = (4/5) x + b
5 = [(4/5)*3] + b
5 = 12/5 + b
b = 13/5
y = (4/5)x + 13/5
Ok, we lmow that the slope is 4/5.
subtract 2.4 from both sides
-4.4 which is how I got the y-intercept
13/5 = 2.6 not 4.4
In solving for b, you took the x-value from one point (x=3) and, for y, you used the x value from the other point (x=-2) instead of y. You should have used y=5, as I did in my derivation. You have to use the x and y values of one known point to get the line to pass though that point.