Subtract 18/42 from 21/60
21/60 - 18/42 is -11/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 60 and 42 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 60 × 7 = 420,
21/60 = 21 × 7/60 × 7 = 147/420 - Likewise, for the 2nd fraction, since 42 × 10 = 420,
18/42 = 18 × 10/42 × 10 = 180/420 - Subtract the two like fractions:
147/420 - 180/420 = 147 - 180/420 = -33/420 - After reducing the fraction, the answer is -11/140
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/60-18/42 21/60-36/42 21/60-18/84 63/60-18/42 21/60-54/42 21/60-90/42