Subtract 45/21 from 90/12
1st number: 7 6/12, 2nd number: 2 3/21
90/12 - 45/21 is 75/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 12 and 21 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 12 × 7 = 84,
90/12 = 90 × 7/12 × 7 = 630/84 - Likewise, for the 2nd fraction, since 21 × 4 = 84,
45/21 = 45 × 4/21 × 4 = 180/84 - Subtract the two like fractions:
630/84 - 180/84 = 630 - 180/84 = 450/84 - After reducing the fraction, the answer is 75/14
- In mixed form: 55/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/12-90/21 90/24-45/21 90/12-45/42 90/36-45/21 90/12-45/63 90/60-45/21 90/84-45/21