In an equation you will find one expressions equal to another. At least one of these expressions will contain an unknown number. The unknown numbers are often called x. When one term (in an equation) is moved across the equal sign, the term goes from plus to minus or from minus to plus.
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Let us study a task:
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We move all the x-terms to one side and all the other terms to the other side of the equal sign:
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Then we contract the x-signs individually and all the other terms individually.
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To find the answer we isolate x on one side of the equal sign. In this task it is done by dividing the expressions on both sides by 7.
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| The answer is: |
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The terms in an equation can contain several factors where one of the factor contains several terms ...
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We can solve equations like that by the procedures shown below:
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In this equation there are main terms with factors containing two terms. This equation does also contain fractions.
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In main terms containing two factors we multiply the two factors.
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All the terms in the equation are multiplied by the common denominator:
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Let us continue..
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We collect all the x-terms on one side of the equal sign and all the other terms on the other side. We then contract all the x-terms on one side of the equal sign and all the other terms on the other side:
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This leads to:
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We now have to isolate x to get the answer. In this case we have to divide the terms on both sides of the equal sign by 11:
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The answer is:
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The example above shows that we can convert an equation with terms containing fractions to an equation with out fractions. We can do this by multiplying all the terms in the equation by the common denominator.
NB! We can not multiply all the fractions by the common denominator when we contract fractions. Do you have an explanation?
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