Subtract 7/8 from 42/30
1st number: 1 12/30, 2nd number: 7/8
42/30 - 7/8 is 21/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 8 is 120
Next, find the equivalent fraction of both fractional numbers with denominator 120 - For the 1st fraction, since 30 × 4 = 120,
42/30 = 42 × 4/30 × 4 = 168/120 - Likewise, for the 2nd fraction, since 8 × 15 = 120,
7/8 = 7 × 15/8 × 15 = 105/120 - Subtract the two like fractions:
168/120 - 105/120 = 168 - 105/120 = 63/120 - After reducing the fraction, the answer is 21/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/30-7/8 42/30-14/8 42/60-7/8 42/30-7/16 42/30-21/8 42/90-7/8 42/30-7/24 42/30-35/8 42/30-7/40 42/30-49/8 42/30-7/56