From Förberedande kurs i matematik 1

Revision as of 06:24, 21 August 2008 (edit) Tekbot (Talk | contribs) m (Robot: Automated text replacement (-[[Bild: +[[Image:)) ← Previous diff		Current revision (07:34, 19 September 2008) (edit) (undo) Tek (Talk | contribs) m
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-	{{NAVCONTENT_START}}	+	We multiply the top and bottom of each fraction by the other fraction's denominator so that they have a common denominator,
-	<center> [[Image:1_2_1c.gif]] </center>	+
-	{{NAVCONTENT_STOP}}	+	{{Displayed math||<math>\frac{1}{6}-\frac{2}{5}=\frac{1\cdot 5}{6\cdot 5}-\frac{2\cdot 6}{5\cdot 6}=\frac{5}{30}-\frac{12}{30}\,</math>.}}
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		+	Then the numerators can be subtracted
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		+	{{Displayed math||<math>\frac{5}{30}-\frac{12}{30}=\frac{5-12}{30}=\frac{-7}{30}=-\frac{7}{30}\,</math>.}}

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Current revision

We multiply the top and bottom of each fraction by the other fraction's denominator so that they have a common denominator,

\displaystyle \frac{1}{6}-\frac{2}{5}=\frac{1\cdot 5}{6\cdot 5}-\frac{2\cdot 6}{5\cdot 6}=\frac{5}{30}-\frac{12}{30}\,.

Then the numerators can be subtracted

\displaystyle \frac{5}{30}-\frac{12}{30}=\frac{5-12}{30}=\frac{-7}{30}=-\frac{7}{30}\,.