The error is in the second step they subtracted 3 from both sides but it was a 3x, which you can not do.
Correction.
9x+18+3x=1
12x+18=1
12x=-17
x=-17/12
Answer:
D.) f(m)=27−3m
Step-by-step explanation:
Given that:
Original rating = 27
Total possible rating points = 30
Drop in rating point per month = 3
m = number of months since release :
Hence,
F(m) = original rating - drop in rating per month * number of months since release
F(m) = 27 - 3(m)
F(m) = 27 - 3m
Draw the one side then. Next to that you draw the other. Make sure there are noticeable differences between the two.