Question

Thomas wants to rent a lawn mower. He has to pay a fixed base cost plus a daily rate for renting the lawn mower. The table shows the amount of money, y, in dollars, that Thomas has to pay for renting the lawn mower for x days: Lawn Mower Rental Number of days(x) Rent (dollars)(y) (x) (y) 0 12 1 21 2 30 3 39 4 48 Which equation best shows the relationship between x and y? y = x + 21 y = 9x + 21 y = 9x + 12 y = x + 12

Answer 1

We first notice that the sequence of numbers:

          12, 21, 30, 39, 48 increases by 9 ($ per day).

We see that these values, related to the days 0, 1, 2, 3, 4 can be written as follows:

12=0*9+12

21=1*9+12

30=2*9+12

39=3*9+12

48=4*9+12

Thus, the price to pay for renting a lawn mower x days is y=9x+12.


Answer: y=9x+12