SOLUTION: Suppose that a car rental agency charges a fixed amount per day plus an amount per mile for renting a car. Heidi rented a car one day and paid $50 for 200 miles. On another day she

Algebra ->  Functions -> SOLUTION: Suppose that a car rental agency charges a fixed amount per day plus an amount per mile for renting a car. Heidi rented a car one day and paid $50 for 200 miles. On another day she      Log On


   



Question 1148939: Suppose that a car rental agency charges a fixed amount per day plus an amount per mile for renting a car. Heidi rented a car one day and paid $50 for 200 miles. On another day she rented a car from the same agency and paid $74 for 360 miles. Find the linear function f(x) (where x is in miles and f(x) is in dollars) that the agency could use to determine its daily rental charges.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
You are given the points:
( 200, 50 )
( 360, 74 )
----------------
Use the general point-slope formula
+%28+f%28x%29+-+50+%29+%2F+%28+x+-+200+%29+=+%28+74+-+50+%29+%2F+%28+360+-+200+%29+
+%28+f%28x%29+-+50+%29+%2F+%28+x+-+200+%29+=+24+%2F+160+
+%28+f%28x%29+-+50+%29+%2F+%28+x+-+200+%29+=+3+%2F+20+
+f%28x%29+-+50+=+%283%2F20%29%2A%28+x+-+200+%29+
+f%28x%29+-+50+=+%283%2F20%29%2Ax+-+30+
+f%28x%29+=+%283%2F20%29%2Ax+%2B+20+
-------------------------------
check:
( 200, 50 )
+f%28x%29+=+%283%2F20%29%2Ax+%2B+20+
+50+=+%283%2F20%29%2A200+%2B+20+
+50+=+30+%2B+20+
+50+=+50+
----------------------
( 360, 74 )
+f%28x%29+=+%283%2F20%29%2Ax+%2B+20+
+74+=+%283%2F20%29%2A360+%2B+20+
+74+=+54+%2B+20+
+74+=+74+
OK