Work out the contents of the brackets first: 2/12-1/4. The common denominator is 12. 4 goes into 12 3 times so 1/4 is 3/12. So we have 2/12-3/12 or (2-3)/12=-1/12. Now we have to multiply this by the number outside the brackets: 12*(-1/12) = -1, because the 12's cancel out leaving -1. The number 12 outside the brackets is positive and the result of the brackets is negative. Positive times negative is negative, so that's why the answer's -1.