the answer is 1/4 or 0.25.
steps:
first look in the parenthesis and notice that the denominator is not the same. set the denominator to 6 for the fraction 1/3 by multiplying 3(2) and 1(2) which makes the fraction 1/6. now add -5/6 and 1/6 inside the parenthesis. you should get -3/6 which you should put in the simplest form: -1/2. now combine -1/2 and -1/2 to get 1/4