Answer:
-47/8.
Step-by-step explanation:
If the line has a slope of -1/8, that means the equation y = mx + b will be y = -1/8x + b.
In this case, we are given a point: (9, -7). That means that x = 9 and y = -7.
-7 = (-1/8)(9) + b
b - 9/8 = -7
b = -56/8 + 9/8
b = -47/8 = -5.875 = -5 and 7/8, which is your y-intercept!
Hope this helps!
Recall that 
. So if 
, we can multiply both sides of the equation by 
to get
