Answer:
The machine makes 45 bottles per minute.
Explanation:
We can first find the slope through this equation:

Since we are given two points, (2,90) and (7,315), we can plug those two points into the formula given above:
= 45
Therefore, m = 45.
Now, we can pick one of the two points given--in this case, I'll use (2,90)--to find the equation of the line:

For (2,90), y1 will be 90, and x1 will be 2. Let's also plug in m:
y - (90) = 45(x - 2)
We can solve for y now to find what y=mx+b is:
y = 45(x-2) + 90
y = 45x
Since the problem asks how many bottles the machine can make per minute, we can plug x = 1: 45(1) = 45
The machine makes 45 bottles per minute.