Subtract 21/5 from 27/42
1st number: 27/42, 2nd number: 4 1/5
27/42 - 21/5 is -249/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 5 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
27/42 = 27 × 5/42 × 5 = 135/210 - Likewise, for the 2nd fraction, since 5 × 42 = 210,
21/5 = 21 × 42/5 × 42 = 882/210 - Subtract the two like fractions:
135/210 - 882/210 = 135 - 882/210 = -747/210 - After reducing the fraction, the answer is -249/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 54/42-21/5 27/42-42/5 27/84-21/5 27/42-21/10 81/42-21/5 27/42-63/5 27/42-21/15 27/42-21/25 27/42-21/35