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If a number is added to the numerator of 5/6 and twice as much is added to the denominator, the result is 3/5. Find the number.

User Dmytro Semenov
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1 Answer

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We are given that a number is added to the numerator of 5/6. If "x" is the number then this can be written mathematically as:


(5+x)/(6)

we also told that twice this number is added to the denominator, this can be written mathematically as:


(5+x)/(6+2x)

We are also told that the result of this operation of 3/5, therefore, we have:


(5+x)/(6+2x)=(3)/(5)

We get an equation with one variable. To solve this equation we will cross multiply the equation, like this:


5(5+x)=3(6+2x)

Now we will apply the distributive property on both parentheses:


25+5x=18+6x

Now we subtract 6x from both sides:


\begin{gathered} 25+5x-6x=18+6x-6x \\ 25-x=9 \end{gathered}

Now we subtract 25 from both sides:


\begin{gathered} 25-25-x=18-25 \\ -x=-7 \end{gathered}

Now we multiply both sides by -1:


x=7

Therefore, the number is 16.

Let's replace the value of "x" in the expression:

User Roomana
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