Subtract 3/90 from 72/84
72/84 - 3/90 is 173/210.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 90 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 84 × 15 = 1260,
72/84 = 72 × 15/84 × 15 = 1080/1260 - Likewise, for the 2nd fraction, since 90 × 14 = 1260,
3/90 = 3 × 14/90 × 14 = 42/1260 - Subtract the two like fractions:
1080/1260 - 42/1260 = 1080 - 42/1260 = 1038/1260 - After reducing the fraction, the answer is 173/210
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 72/84-6/90 72/84-9/90 72/84-15/90 72/84-21/90