Subtract 84/16 from 42/21
1st number: 2 0/21, 2nd number: 5 4/16
42/21 - 84/16 is -13/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 16 is 336
Next, find the equivalent fraction of both fractional numbers with denominator 336 - For the 1st fraction, since 21 × 16 = 336,
42/21 = 42 × 16/21 × 16 = 672/336 - Likewise, for the 2nd fraction, since 16 × 21 = 336,
84/16 = 84 × 21/16 × 21 = 1764/336 - Subtract the two like fractions:
672/336 - 1764/336 = 672 - 1764/336 = -1092/336 - After reducing the fraction, the answer is -13/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/21-84/16 42/21-84/32 42/63-84/16 42/21-84/48 42/21-84/80