Write the equation of the line in slope intercept form with the given information: through the points (-1,-9) and (2,6) how would you do this?

Slope intercept form isy=mx+b
m=slope
b=y intercept
ok so to find the slope when given 2 points you do
slope=(y1-y2)/(x1-x2)

(x,y)
(-1,-9)
(2,6)
x1=-1
y1=-9
x2=2
y2=6
subsitute
slope=(-9-6)/(-1-2)
slope=(-13)/(-3)
slope=13/3

y=13/3x+b
subsitute a given point to find b
(2,6)
x=2
y=6
6=13/3(2)+b
6=26/3+b
subtract 26/3 from both sides
6-26/3=b
6=18/3
18/3-26/3=8/3
8/3=b

the equation si
y=(13/3)x+8/3

It would be 18 cm