find the equation
alrighty, the slope is rise/run
from (21,-3) to (28,-1)
rise is from -3 to -1 or a rise of 2
run is form 21 to 28 or a run of 7
so slope is 2/7
y=2/7x+b
find b which is the y intercept
alirhgty
use (21,-3)
x=21 and y=-3
-3=(2/7)(21)+b
-3=42/7+b
-3=6+b
-9=b
y=2/7x-9
the y intercept is (0,-9
the x intercept is where y=0
0=2/7x-9
9=2/7x
63/2=x
x intercept is (63/2,0) or (31.5,0)
y intercept is (0,-9)