Subtract 70/21 from 45/54
1st number: 45/54, 2nd number: 3 7/21
45/54 - 70/21 is -5/2.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 54 and 21 is 378
Next, find the equivalent fraction of both fractional numbers with denominator 378 - For the 1st fraction, since 54 × 7 = 378,
45/54 = 45 × 7/54 × 7 = 315/378 - Likewise, for the 2nd fraction, since 21 × 18 = 378,
70/21 = 70 × 18/21 × 18 = 1260/378 - Subtract the two like fractions:
315/378 - 1260/378 = 315 - 1260/378 = -945/378 - After reducing the fraction, the answer is -5/2
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/54-70/21 45/54-70/42 45/54-70/63