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- 52
- êê MULTIPLYING FRACTIONS, ELEMENTARY LEVEL
-
- è In this section we will be looking at multiplying positive frac-
- tions.ïWhen you multiply two positive fractions, the answer is always
- positive.ïThe procedure is to multiply the two numerators and the
- two denominators, express the resulting numerator and denominator in
- prime factored form, cancel any like factors that occur on the top and
- bottom, and finally multiply any remaining factors.ïThe positive frac-
- tions and zero are described in the following list.
-
- êêêë Positive Fractions
-
- #êêêï╚è╔è╩è╦è╠è═è╬ ...
- êêêï1è1è1è1è1è1è1
-
- #êêêï╚è╔è╩è╦è╠è═è╬ ...
- êêêï2è2è2è2è2è2è2
-
- #êêêï╚è╔è╩è╦è╠è═è╬ ...
- êêêï3è3è3è3è3è3è3
- êêêè .
- êêêè .
- êêêè .
-
- Example 1)èMultiply the fractions 4/15 and 5/6.
-
- è First, you should multiply the two numerators and the two denomi-
- nators.
- êêêë 4è5ê 4∙5
- #êêêë── ∙ ─è=è────
- êêêë15è6ê15∙6
-
- Next, you should express each number in prime factored form.
-
- êêêë4∙5êè 2∙2∙5
- #êêêè ────è =è ───────
- êêêè 15.6êï3∙5∙2∙3
-
- Then, cancel out any like factors that occur on the top and bottom.
-
- êêêë 2∙2∙5êè 2
- #êêêè ───────è =è ───
- êêêè 3∙5∙2∙3êï3∙3
-
- Finally, you should multiply any remaining factors.
-
- êêêêè2êï2
- #êêêê ───è =è ─
- êêêê 3∙3êï9
-
- Thus, the product of 4/15 and 5/6 is 2/9.
-
-