Subtract 7/8 from 12/42
12/42 - 7/8 is -33/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
12/42 = 12 × 4/42 × 4 = 48/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
7/8 = 7 × 21/8 × 21 = 147/168 - Subtract the two like fractions:
48/168 - 147/168 = 48 - 147/168 = -99/168 - After reducing the fraction, the answer is -33/56
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 24/42-7/8 12/42-14/8 12/84-7/8 12/42-7/16 36/42-7/8 12/42-21/8 12/42-7/24 60/42-7/8 12/42-35/8 12/42-7/40 84/42-7/8 12/42-49/8 12/42-7/56