Question 347455
{{{(9/30)-(5/30)-(12/30)=(-8/30)=highlight(-4/15)}}}

Since they all have common denominators you can just look at the numerators for the subtraction.  

The problem essentially reads {{{9 - 5 - 12.}}}  {{{9-5 = 4}}}  {{{4-12 = -8}}}  Therefore the answer is {{{-8/30}}}  Simplifying that gives you {{{highlight(-4/15)}}}.