SOLUTION: A rental car costs $25 plus afixed charge per mile driven. The total chrge for 210 miles of use was $89. Write an equation for the cost,C(in dollars), in terms of the mile driven x

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Question 59945: A rental car costs $25 plus afixed charge per mile driven. The total chrge for 210 miles of use was $89. Write an equation for the cost,C(in dollars), in terms of the mile driven x.
Answer by tutorcecilia(2152) About Me  (Show Source):
You can put this solution on YOUR website!
y=mx+b [Use the slope-intercept format for the equation of this line since the y-intercept is given (25) and you can find the slope from the information given:
$25=the flat-fee (y-intercept)
210miles=one of the values of (x) miles
$89=one of the values for the total (y) when x=210
.
C(x)=mx+b
C(210)=m(210)+25 [Plug-in the given values and solve for m]
89=m(210)+25 [Solve for the slope (m)]
89-25=210m+25-25
64=210m
64/210=m
32/105=m
.
C(x)=(32/105)x+25 [Plug-in the value of the slope and the y-intercept for the equation of the line.