# Thread: Elimination

1. ## Elimination

ok so i have a solving problem about substitution
Taxis in a certain city charge a flat fee plus an additional charge per kilometer. Russ was charge $3.20 for a 5-km ride and Kylie was charged$4.20 for a 9-km ride. Someone lay out the 2 equations since i can't seem to figure out the two equations?

2. You have the coordinates (5,3.2) and (9,4.2)

Propose a linear solution of

$\displaystyle C = ad+b$

where

C = cost of fair
d = distance travelled
a = the rate per kilometre travelled
b = flagfall amount

$\displaystyle a = \frac{4.2-3.2}{9-5}= \frac{1}{4} = 0.25$

$\displaystyle C = 0.25d+b$ using (5,3.2) to find b

$\displaystyle 3.2 = 0.25\times 5+b$

$\displaystyle b= 1.95$

so we have

$\displaystyle C = 0.25b+1.95$