Math Is Fun Forum

actually I found this quastion in a math forum

Find a,b,c,d,e,f,g if they are natural numbers  N = 1,2,3,..................

and

7/30 = 1/a + 1/b + 1/ c + 1/d + 1/ e + 1/f + 1/g

  last thing

How to expand the fraction . for example

5/121 is divided in two ways . the first one is longer than the other

can you expalin it with a small example like

7/30 .
Divide it to 7 fractions.

Thank you

allways put it in  possitive ?? right

can you look at this

http://en.wikipedia.org/wiki/Greedy_algorithm_for_Egyptian_fractions

(simplifying the second term in this replacement as necessary). For instance:

7/15 = 1/3+2/15  ???

the remainder should be 1

that means it should be

7/15 = 1/3 + 1/45 , should not it ? According to the rulle

It does not make sens but the rule says that

I knew it from someone .
and I read it again in a Teaching Package.
but I don't have this package now > so I want to be sure aout this infornmation.

WoOoOoW
tHaNk YoU So MuCh

are there the solutions ?

woOoOow

I will think about it , thank u for the hint for a new problem
I tried to prove this rule >>> (n-1+j)C j , I wondered from where the Combinations came ?

I have quastion is there a link for IMO training in this forum.:

actually I read  a rule says

if x1,x2,x3,........,xn Integers numbers but not negative
so the number of solutions for x1+x2+x3+x4+........+xn=j

is
(n-1+j)C j 

I Wanna be sure if is it right ?

Sorry there was a mistake in the quastion

I fixed the mistake

thank u

thank u bobbym