# SUBTRACTION: Problem 2

Rule 19:
To subtract, the denominators must be equal. You essentially following the same steps as in addition.
1.
Build each fraction so that both denominators are equal.
2.
Combine the numerators according to the operation of subtraction or additions.
3.
The denominators will be the denominator of the built-up fractions.
4.

Problem 2:
Solution:
The denominators are different, so you must build each fraction to a form where they both have the same denominator. Since 5 divides into 15 evenly, you only have to build the fraction to an equivalent fraction with a denominator of 15. .
can now be written .
Combine the numerators for the numerator in the answer:

4 - 9 = -5.
This fraction now needs to be reduced.

Check:
Now prove to yourself with your calculator that your answer is correct. Calculate 4 divided by 15, calculate 3 divided by 5, and combine the results. Now divide -1 by 3. Both answers should be the same. If you are correct, the answers are the same (equivalent) and you have successfully combine two fractions using subtraction.

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