We can take out b2cd (is this b^2cd?) because it's common to all three terms and just deal with fractions: -1/3-5/6+1. The last term isn't a fraction, but it's 1*b2cd. Put these over the common denominator 6: (-2-5+6)/6=-1/6. (-1/3 is the same as -2/6 and 1 is the same as 6/6.) the factor we took out can now go back into the answer: -1/6b2cd.