
Tamara J. answered 10/08/12
Math Tutoring - Algebra and Calculus (all levels)
when you add/subtract fractions, you want to find a common denominator so that all you would need to do is add/subtract the numerators...
for the problem you are asking about, 1/2 - 1/8, you would multiply 1/2 by 4/4 (notice that 4/4=1 which wouldn't change the value of the number you're multiplying it by)
so, (1/2)*(4/4) = 4/8
all that is left to do now is subtract: 4/8 - 1/8 = (4-1)/8 = 3/8
make sure you didn't leave a part of the problem out when you were writing it down, if not then check to see that you looked up the answer for the problem in the right chapter/section, if you did then it's probably just a typo in the text