Question

A taxi ride costs $3 plus $2 for each mile driven. You spend $39 on a taxi. This can be modeled by the equation 2m + 3 = 39,

where m represents the number of miles driven. How long was your taxi ride?

Answer 1

So first we lay out the equation
39 = 2m + 3

Then we need to get the variable by itself by cancelling out the 3 on each side of the equation, like so:
39 - 3 = 2m + 3 - 3

Our simplified result would then be:
36 = 2m

*since we cancelled out the 3 on both sides we don’t need it to solve from here on out*

So then in order to get the ‘m’ by itself we must divide on both sides by 2 since the 2 is *multiplying* by ‘m’.

36/2 = 2m/2

Once simplified your answer would be:

18 = m

So now let’s check our answer since we know m=18:
39 = 2(18) + 3
39 = 36 + 3
39 = 39
This can verify that the ride was 18 miles long. Hope this helps! :)