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Math Help - factoring

  1. #1
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    factoring

    14 + .80x =46
    14 -14 +.80x =46 -14
    .80x= 32
    .80 80 or.80x/.80 32/.80 the answer is 40, but how exactly does .80x/.80 32/.80 = 40 meaning the mechanics of
    I know x equals 40, but what i want to know is how to single out the x to the left to get 40
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  2. #2
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    Quote Originally Posted by Leona_Marie View Post
    14 + .80x =46
    14 -14 +.80x =46 -14
    .80x= 32
    .80 80 or.80x/.80 32/.80 the answer is 40, but how exactly does .80x/.80 33/.80 = 40 meaning the mechanics of
    <br />
0.80x = 32<br />

    <br />
x = \frac {32}{0.8} = \frac {32} {\frac{4}{5}} = \frac {32 \cdot 5}{4} = 40<br />
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  3. #3
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    Quote Originally Posted by metlx View Post
    <br />
0.80x = 32<br />

    <br />
x = \frac {32}{0.8} = \frac {32} {\frac{4}{5}} = \frac {32 \cdot 5}{4} = 40<br />
    I understood all the way to the 32/4/5 whats 32.5/ where did yuou get .5and how did you end up with jus 4 as denominator. and how do you turn 32.5/4 into 40 ?
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  4. #4
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    there is a rule for it.

    <br /> <br />
\frac {x}{\frac{y}{z}} = \frac { x\cdot z}{y}<br />

    or more common example
    <br />
\frac{100}{\frac{20}{2}} = \frac {100}{10} = 10 = \frac{100 \cdot 2}{20}<br />

    OR
    <br />
\frac{4}{2}=\frac{\frac{4}{1}}{\frac{2}{1}} = \frac {4\cdot1}{2\cdot1}<br />
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  5. #5
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    Quote Originally Posted by metlx View Post
    there is a rule for it.

    <br /> <br />
\frac {x}{\frac{y}{z}} = \frac { x\cdot z}{y}<br />

    or more common example
    <br />
\frac{100}{\frac{20}{2}} = \frac {100}{10} = 10 = \frac{100 \cdot 2}{20}<br />

    OR
    <br />
\frac{4}{2}=\frac{\frac{4}{1}}{\frac{2}{1}} = \frac {4\cdot1}{2\cdot1}<br />
    Ive never heard of it but thank you just the same leona
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  6. #6
    Senior Member mollymcf2009's Avatar
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    Quote Originally Posted by metlx View Post
    <br />
0.80x = 32<br />

    <br />
x = \frac {32}{0.8} = \frac {32} {\frac{4}{5}} = \frac {32 \cdot 5}{4} = 40<br />

    When you have a fraction in the denominator of a fraction:

    \frac{32}{\frac{4}{5}}

    you can multiply the top of the fraction by the reciprocal of the bottom fraction:

    Think of 32 being the same thing as \frac{32}{1}

    So,

    \frac{\frac{32}{1}}{\frac{4}{5}}

    = \frac{32}{1}\cdot\frac{5}{4}

    Then just multiply across each fraction:

    \frac{160}{4} = 40
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  7. #7
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    Quote Originally Posted by mollymcf2009 View Post
    When you have a fraction in the denominator of a fraction:

    \frac{32}{\frac{4}{5}}

    you can multiply the top of the fraction by the reciprocal of the bottom fraction:

    Think of 32 being the same thing as \frac{32}{1}

    So,

    \frac{\frac{32}{1}}{\frac{4}{5}}

    = \frac{32}{1}\cdot\frac{5}{4}

    Then just multiply across each fraction:

    \frac{160}{4} = 40
    thank you molly this makes sense
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