Subtract 21/12 from 7/90
1st number: 7/90, 2nd number: 1 9/12
7/90 - 21/12 is -301/180.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 12 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 90 × 2 = 180,
7/90 = 7 × 2/90 × 2 = 14/180 - Likewise, for the 2nd fraction, since 12 × 15 = 180,
21/12 = 21 × 15/12 × 15 = 315/180 - Subtract the two like fractions:
14/180 - 315/180 = 14 - 315/180 = -301/180
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/90-21/12 7/90-42/12 7/90-21/24 21/90-21/12 7/90-63/12 7/90-21/36 35/90-21/12 7/90-21/60 49/90-21/12 7/90-21/84