Subtract 30/4 from 30/21
1st number: 1 9/21, 2nd number: 7 2/4
30/21 - 30/4 is -85/14.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 4 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 21 × 4 = 84,
30/21 = 30 × 4/21 × 4 = 120/84 - Likewise, for the 2nd fraction, since 4 × 21 = 84,
30/4 = 30 × 21/4 × 21 = 630/84 - Subtract the two like fractions:
120/84 - 630/84 = 120 - 630/84 = -510/84 - After reducing the fraction, the answer is -85/14
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 60/21-30/4 30/21-60/4 30/42-30/4 30/21-30/8 90/21-30/4 30/21-90/4 30/63-30/4 30/21-30/12 30/21-30/20 30/21-30/28