Subtract 21/50 from 42/72
42/72 - 21/50 is 49/300.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 50 is 1800
Next, find the equivalent fraction of both fractional numbers with denominator 1800 - For the 1st fraction, since 72 × 25 = 1800,
42/72 = 42 × 25/72 × 25 = 1050/1800 - Likewise, for the 2nd fraction, since 50 × 36 = 1800,
21/50 = 21 × 36/50 × 36 = 756/1800 - Subtract the two like fractions:
1050/1800 - 756/1800 = 1050 - 756/1800 = 294/1800 - After reducing the fraction, the answer is 49/300
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/72-21/50 42/72-42/50 42/72-63/50