
Elementary Math Fractions, Percentages, Word Problems, Equations, Inequations, Factorization, Expansion 
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September 28th, 2019, 02:57 AM  #1 
Newbie Joined: Sep 2019 From: ireland Posts: 3 Thanks: 0  pls help
3n+21/n+3 is given.show all the possible values so that n is a natural number and the final poduct of the equation is also a natural number

September 28th, 2019, 04:34 AM  #2 
Senior Member Joined: Jun 2014 From: USA Posts: 620 Thanks: 52 
Does $\frac{3n+21}{n+3} = \frac{n+7}{\frac{n}{3}+1}$? If so, I think that means $n$ must always be divisible by 3, correct? Maybe not...? We might also notice that $\frac{n+7}{n+3}$ must be a natural number, correct? Do either of these things help? What have you tried so far? 
September 28th, 2019, 08:31 AM  #3 
Math Team Joined: May 2013 From: The Astral plane Posts: 2,304 Thanks: 961 Math Focus: Wibbly wobbly timeywimey stuff.  