Subtract 45/21 from 30/45
1st number: 30/45, 2nd number: 2 3/21
30/45 - 45/21 is -31/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
30/45 = 30 × 7/45 × 7 = 210/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
45/21 = 45 × 15/21 × 15 = 675/315 - Subtract the two like fractions:
210/315 - 675/315 = 210 - 675/315 = -465/315 - After reducing the fraction, the answer is -31/21
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/45-45/21 30/45-90/21 30/90-45/21 30/45-45/42 90/45-45/21 30/45-45/63