Subtract 21/12 from 90/15
1st number: 6 0/15, 2nd number: 1 9/12
90/15 - 21/12 is 17/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 15 and 12 is 60
Next, find the equivalent fraction of both fractional numbers with denominator 60 - For the 1st fraction, since 15 × 4 = 60,
90/15 = 90 × 4/15 × 4 = 360/60 - Likewise, for the 2nd fraction, since 12 × 5 = 60,
21/12 = 21 × 5/12 × 5 = 105/60 - Subtract the two like fractions:
360/60 - 105/60 = 360 - 105/60 = 255/60 - After reducing the fraction, the answer is 17/4
- In mixed form: 41/4
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/15-42/12 90/30-21/12 90/15-21/24 90/15-63/12 90/45-21/12 90/15-21/36 90/75-21/12 90/15-21/60 90/15-21/84