Subtract 70/42 from 28/72
1st number: 28/72, 2nd number: 1 28/42
28/72 - 70/42 is -23/18.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 72 and 42 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 72 × 7 = 504,
28/72 = 28 × 7/72 × 7 = 196/504 - Likewise, for the 2nd fraction, since 42 × 12 = 504,
70/42 = 70 × 12/42 × 12 = 840/504 - Subtract the two like fractions:
196/504 - 840/504 = 196 - 840/504 = -644/504 - After reducing the fraction, the answer is -23/18
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 56/72-70/42 28/72-70/84 84/72-70/42