11.3k views
2 votes
In a certain fraction, the denominator is 3 less than the numerator. If 1 is added to both the numerator and denominator, the resulting fraction is equal to 10/7 Find the original fraction.

User Limavolt
by
6.8k points

1 Answer

4 votes

The original fraction has a denominator that is 3 less than the numerator. If we define the numerator as x, then the denominator is x-3, and the fraction can be written as x/(x-3).

If 1 is added both to the numerator and denominator, the resulting fraction is equal to 10/7.

Then, we can write:


\begin{gathered} (x+1)/((x-3)+1)=(10)/(7) \\ (x+1)/(x-2)=(10)/(7) \\ 7(x+1)=10(x-2) \\ 7x+7=10x-20 \\ 7x-10x=-20-7 \\ -3x=-27 \\ x=(-27)/(-3) \\ x=9 \end{gathered}

With the value of x, we can replace it in the fraction and know the value of it:


(x)/(x-3)=(9)/(9-3)=(9)/(6)=(3)/(2)

Answer: The fraction is 9/6, that can be simplified to 3/2 or 1.5.

User Guillaume Berche
by
6.9k points