A) C(7) represents the cost of an Uber for 7 miles. Since 'm' is the cost for m miles, '7' is the cost for 7 miles.
B) If Todd's total bill was $30, that means the cost (C) is 30. Replace C with 30.
30 = 1.5m+4.5
Now solve this equation.
30-4.5 = 1.5m+4.5-4.5
25.5 = 1.5m
m = 17
If Todd's total bill was $30, his Uber ride was 17 miles.
