Subtract 7/8 from 28/42
28/42 - 7/8 is -5/24.
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,
28/42 = 28 × 4/42 × 4 = 112/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
7/8 = 7 × 21/8 × 21 = 147/168 - Subtract the two like fractions:
112/168 - 147/168 = 112 - 147/168 = -35/168 - After reducing the fraction, the answer is -5/24
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/42-7/8 28/42-14/8 28/84-7/8 28/42-7/16 84/42-7/8 28/42-21/8 28/42-7/24 28/42-35/8 28/42-7/40 28/42-49/8 28/42-7/56