9 tenths - 3 tenths = 6 tenths. this is true the same way that 9 minus 3 = 6. In reality the tenths make both numbers decimals, but in this case the "tenths" is just a classification of the number and it doesn't effect the answer.
9 tenths - 3 tenths = 6 tenths. This problem is just a reflection on basic math. If you take away the word tenths you have the basic problem 9 - 3 = 6. In math, usually the word tenths means that it is being converted to a decimal place (the first to be exact) but in the case, it is just a type of measurement.
Before the mechanic worked on it, it cost .09 (cents) per mile. After the mechanic worked on it, it cost .08 (cents) per mile. Divide the number of gallons by the miles in each case and multiply the result by 4.
