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If the numerator of a fraction is increased by 3, the fraction becomes 3/4. If the denominator is decreased by 7, the fraction becomes 1.

What is the numerator of the fraction?

User Jason Rowe
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2 Answers

4 votes
Hey there!

n=numerator and d=denominator
(n+3)/d=3/4
n/(d+7)=1
n=d+7
(d+7+3)/d=3/4 substitute d+7 for n.
(d+10)/d=3/4

) 4(d+10)=3d multiply each side by 4d
4d+40=3d=-40
n=-40+7
n=-33
User Noirbizarre
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5 votes

Answer: The numerator of the given fraction is 9.

Step-by-step explanation: Given that if the numerator of a fraction is increased by 3, the fraction becomes
(3)/(4) and if the denominator is decreased by 7, the fraction becomes 1.

We are to find the numerator of the function.

Let x and y represents the numerator and denominator of the given function.

Then, according to the given information, we have


(x+3)/(y)=(3)/(4)\\\\\Rightarrow 4(x+3)=3y\\\\\Rightarrow 4x+12=3y\\\\\\\Rightarrow y=(4x+12)/(3)~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(i)

and


(x)/(y-7)=1\\\\\Rightarrow x=y-7\\\\\Rightarrow y=x+7~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~(ii)

Equating the values of y from equations (i) and (ii), we get


(4x+12)/(3)=x+7\\\\\Rightarrow 4x+12=3(x+7)\\\\\Rightarrow 4x+12=3x+21\\\\\Rightarrow 4x-3x=21-12\\\\\Rightarrow x=9.

Thus, the numerator of the given fraction is 9.

User Enriquein
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