Subtract 90/49 from 81/80
1st number: 1 1/80, 2nd number: 1 41/49
81/80 - 90/49 is -3231/3920.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 49 is 3920
Next, find the equivalent fraction of both fractional numbers with denominator 3920 - For the 1st fraction, since 80 × 49 = 3920,
81/80 = 81 × 49/80 × 49 = 3969/3920 - Likewise, for the 2nd fraction, since 49 × 80 = 3920,
90/49 = 90 × 80/49 × 80 = 7200/3920 - Subtract the two like fractions:
3969/3920 - 7200/3920 = 3969 - 7200/3920 = -3231/3920
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 81/80-90/98