Question 253894
You are right in that the slope, m, is 8.
We use Y = mx + b as
Y = 3x + b.
Pick a point (0,-15) to get
-15 = 3*0 + b
Solve for b to get
b = -15
The equation is
Y = 8x - 15
Place (6,7,8) in for x to get
33, 41,,49.