Question 157465
if it's a straight multiplication which is what it looks like then you don't need to find a common denominator.
all you need to do is multiply all the numerators and multiply all the denominators and you get the answer after reducing to the simplest form.
formula as i see it is {{{(-15/42)*(1/8)*(-21/17)*(-1/17)}}}
this becomes {{{(-15*1*-21*-1)/(42*8*17*17)}}}
which becomes {{{(-15*1*-1*-1)/(2*8*17*17)}}}
the -21 on top was divided into the 42 on the bottom to become -1/2.
which then becomes {{{-15/4624}}}