A taxi ride where the total fare is $3, $2 for every mile travelled plus a $1 tip and the original cost of $20.
First write a formula that expresses the cost of the ride:
Total cost= Flat fee + Mileage + Tip
Now let's drop in what we know:
20= 3+2 (miles) +1 - we know the total cost is 20, the fee of 3, the tip of 1 and the cost per mile of 2. The only thing we don't know is the number of miles. So let's solve for that.
Subtract 3 and 1 from both sides to get:
16=2(miles)
Divide both sides by 2:
8=miles
Therefore, you traveled 8 miles.