ALGEBRA help?

crazy hair: ALGEBRA…………………………………?
A car rental charges $ 39 to rent a car plus an additional $ .25/mile driven. Another company charges $ 35 to rent the car plus #.35/mile. At how many miles driven will the prices be the same?

Answers and Views:

Answer by James
Set equations equal to each other…solve for x

39 + .25x = 35 + .35x

39 = 35 + .10x

4 = .10x

x = 40

Answer by Amanda
With word problems it is good to figure out what they are asking for, in this case, it is “how many miles driven will the prices be the same?” So we need to know miles. Assign a variable to the thing that we want to know, in this case miles, so let M = miles

The next step is to build an equation, in other words turn the words into mathematical symbols that are easier to work with. The first sentence can be turned into: 39 + 0.25M (remember M = miles). The second sentence can be turned into 35 + 0.35M.

Now we want to know the situation where the miles driven would mean the same price for either car. So we use the equation: 39 + 0.25M = 35 + 0.35M. This is because either expression alone would give us a price if we figure them out separately but we want to figure out M so that we can solve our word problem. From here just solve for M. You should get M = 40

Knowing that, most teachers like you to state the answers to word problems back into words so, “At 40 miles, the prices for both rental cars will be the same.”

You can test this answer by substituting 40 for M in the original equation.
39 + 0.25(40) = 35 + 0.35(40) —> 40=40, which is true so our answer is correct

Answer by Dakota
40 Miles…

Answer by DoubleJay
39 + .25x = 35 + .35x

39 = 35 + .10x

4 = .10x

x = 40