Subtract 72/20 from 16/42
1st number: 16/42, 2nd number: 3 12/20
16/42 - 72/20 is -338/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 42 × 10 = 420,
16/42 = 16 × 10/42 × 10 = 160/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
72/20 = 72 × 21/20 × 21 = 1512/420 - Subtract the two like fractions:
160/420 - 1512/420 = 160 - 1512/420 = -1352/420 - After reducing the fraction, the answer is -338/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 32/42-72/20 16/84-72/20 16/42-72/40 48/42-72/20 16/42-72/60 80/42-72/20