SOLUTION: After sitting in a taxi for 9 minutes, Sally realizes the cost of her ride is $9.05. Three minutes later the cost was $10.40. How much will the ride be in 30 minutes?

Algebra ->  Sequences-and-series -> SOLUTION: After sitting in a taxi for 9 minutes, Sally realizes the cost of her ride is $9.05. Three minutes later the cost was $10.40. How much will the ride be in 30 minutes?      Log On


   

Question 1084005: After sitting in a taxi for 9 minutes, Sally realizes the cost of her ride is $9.05.
Three minutes later the cost was $10.40. How much will the ride be in 30 minutes?
Answer by josgarithmetic(39629) About Me  (Show Source):
You can put this solution on YOUR website!
x, time
y, cost

Points (9, 9.05) and (12, 10.4)

rate %2810.4-9.05%29%2F3=0.45
y=0.45x%2Bb
b=y-0.45x
b=9.05-0.45%2A9
b=5
-
highlight_green%28y=0.45x%2B5%29


30 minutes after the just traveled 9 minutes would be 39 minutes.
y=0.45%2A39%2B5
y=22.55


If the whole ride is only 30 minutes, y=0.45%2A30%2B5=18.5.