__/__x__+__x__x__/__+__x__=100
\(\frac{\bigcirc{}}{\bigcirc{}}*\bigcirc{}+\frac{\bigcirc{}*\bigcirc{}*\bigcirc{}}{\bigcirc{}}+\frac{\bigcirc{}}{\bigcirc{}}=100\\ \frac{\bigcirc{}*\bigcirc{}}{\bigcirc{}}+\frac{\bigcirc{}*\bigcirc{}*\bigcirc{}}{\bigcirc{}}+\frac{\bigcirc{}}{\bigcirc{}}=100\\\)
100 is not a ver big number
ans one number on the bottom must cancel with something on the top of each each fraction
so I am guessing that the numbers on the bottom are probably 1, 2 and 3
so this is my initial guess
\(\frac{9*\bigcirc{}}{3}+\frac{4*\bigcirc{}*\bigcirc{}}{2}+\frac{\bigcirc{}}{1}=100\\ \text{this cancels to}\\ (3*\bigcirc)+(2*\bigcirc*\bigcirc)+\bigcirc=100 \)
What numbers are left that have not been used yet
5,6,7 and 8
2*5*7=70
3*8=24
70+24+6=100 
(2*\bigcirc)+(3*\bigcirc*\bigcirc)+\bigcirc=100
\(\begin{align}\\ 24+70+6&=100\\ (3*8)+(2*5*7)+6&=100\\~\\ \frac{9*8}{3}+\frac{4*5*7}{2}+\frac{6}{1}&=100\\ \end{align} \)
Of course I had to play with the numbers a little bit more than that but I am trying to give people an idea of how to tackle problems like this 
