A trailer is rented at $30 per day plus a charge per mile of use. The trailer traveled 25 miles in one day and the total charge was $130. Which equation can be used to find the charge x, in dollars, per mile traveled?

30x + 25 = 130

30x + 25x = 130

30 + 25x = 130

30 + 25 = 130x

Question

A trailer is rented at $30 per day plus a charge per mile of use. The trailer traveled 25 miles in one day and the total charge was $130. Which equation can be used to find the charge x, in dollars, per mile traveled? 

 30x + 25 = 130 

 30x + 25x = 130 

 30 + 25x = 130 

 30 + 25 = 130x

anonymous · Answer

30x + 25 = 130
 30x + 25x = 130
 30 + 25x = 130
 30 + 25 = 130x

anonymous · Answer

the independent variable here are the miles

anonymous · Answer

we know the trailer cost $30 per day, nothing changes that
what we don't know is the price per mile

however, 15 miles and the $30 fee accounted for $130
we know it travelled 15 miles
we don't know the cost for miles (x)

anonymous · Answer

Alright

anonymous · Answer

ok we have 15 miles and what will give us a fee?

anonymous · Answer

15 miles alone no fee. just miles

anonymous · Answer

Omg. I am not good at this. Math. Is. Terrible. I think you should just give up now...

anonymous · Answer

:)

anonymous · Answer

well the $30 fee does not depend on the mileage. if the trailer just sit there in the street and the sun shines on it. no milega and still $30

anonymous · Answer

so the 30 should NOT be multiplied with the "cost per mile"

anonymous · Answer

(cost per mile = x )

anonymous · Answer

the cost per mile should also not be multiplied with what you pay for everything. that would mean you treat the payment like miles and then compute cost per payment mile?? not the way to go! (so 130 also should not  get x)

anonymous · Answer

well cost per mile times miles will give you the total mileage cost.

if the cost per mile is $7, then 10 miles would cost - 10x costpermile, or 10x$7 = $70

anonymous · Answer

can you understand briefly, how the cost per mile is computed?

anonymous · Answer

Kind of..Sorry, I really am not good at this..:/

anonymous · Answer

your answer is this:

30 + 25x = 130
^fixed cost for renting the trailer, this doesn't depend on miles so we don't multiply with miles

30 + 25x = 130
                   ^total payment, consisting of fixed cost and mileage cost

30 + 25x = 130
         ^computation of cost due to mileage. more mileage = more cost.
           every mile cost x dollars. so 25*x gives cost for 25 miles

30 + 25x = 130