Subtract 15/49 from 18/21
18/21 - 15/49 is 27/49.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 49 is 147
Next, find the equivalent fraction of both fractional numbers with denominator 147 - For the 1st fraction, since 21 × 7 = 147,
18/21 = 18 × 7/21 × 7 = 126/147 - Likewise, for the 2nd fraction, since 49 × 3 = 147,
15/49 = 15 × 3/49 × 3 = 45/147 - Subtract the two like fractions:
126/147 - 45/147 = 126 - 45/147 = 81/147 - After reducing the fraction, the answer is 27/49
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 36/21-15/49 18/21-30/49 18/42-15/49 18/21-15/98 54/21-15/49 18/21-45/49 18/63-15/49 90/21-15/49 18/21-75/49