Answer:
Y=15x
Step-by-step explanation:
<h2>Okay so let's approach this problem!</h2><h2 />
X is books and Y is total cost
Let's find the slope!
Y2-Y1/ X2-X1
Just replace


The slope is 15

Now replace x and y with coordinates and solve

The final equation:
y = 15x
That's it! If you have any questions please ask! Brainliest Appreciated.
Answer: slope is 0
to find the slope , you have to subtract y-es and divide them by x-es.(delta y/ delta x)
so,
(-6,-2) (-7,-2)
slope: -2-(-2)/-7-(-6)
slope:0/ -1
slope: 0
which looks on the graph like this: