First, find a common denominator. This would be 35, as it is the smallest number that is a multiple of 7 and 5. Now, you are going to multiply each fraction by the number you get when you divide the new denominator by the old. Below are all of the steps in order:
- Multiply each fraction to get the denominator to 35. Remember that we have to multiply both the numerator and denominator to keep our fractions equal!
- Subtract numerators over the common denominator
The answer is
.