Subtract 30/90 from 7/28
7/28 - 30/90 is -1/12.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 28 and 90 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 28 × 45 = 1260,
7/28 = 7 × 45/28 × 45 = 315/1260 - Likewise, for the 2nd fraction, since 90 × 14 = 1260,
30/90 = 30 × 14/90 × 14 = 420/1260 - Subtract the two like fractions:
315/1260 - 420/1260 = 315 - 420/1260 = -105/1260 - After reducing the fraction, the answer is -1/12
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/28-30/90 7/28-60/90 7/56-30/90 21/28-30/90 7/84-30/90 35/28-30/90 49/28-30/90