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:
a.
the function we are working with
Step-by-step explanation:
f(x) is functions notation which means the output for the function being worked with. It is the y value hence y=f(x).