The answer is 4x-8+4y i think?
When it says varies directly, it means that y and x are going to be on opposite sides of the equals sign and that there is a constant, k,
y=kx
Plug in (5,100)
100=k(5)
K=20
The cost to the nearest sent is 0.14
This is because you can round the .136 up to the nearest hundredths place.
