C because PEMDAS
(Please excuse my dear aunt sally)
The correct answer is 3) $15
It seems that the first row was before the fixed amount was charged.
Days 1 and 2 are in a constant change of 1x and 15y.
ok turn 7/5 and 3/5 into a decimal
here let me help you
3/5 = 0.6
7/5 = 1.4
1.4 / 0.6 = 2.3 repeat
then turn it back into a fraction which is 2 3/10
this is how I do it by the way.
This is the graph of 1/x moved 4 units to the left
so its f(x) = 1 / (x + 4)
C