It would be $7.50 because 4 ounces equals $1 so 30/4 =7.5
It's linear
If you evaluate x when it's 0 you'll get the cut in y, that means the function will pass on (0,7)
The formula for linear functions is y=mx +b
In this case b is 7
M=7-5/0+1
M=2
Now you just write the function down, it would be
F(x) =2x + 7
Just plug in the x-values into the given equation to find. For 9-19-19 whatever the number is correlated to how much the graph is being moved down or up and the x is your slope.
