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