Subtract 90/81 from 7/49
1st number: 7/49, 2nd number: 1 9/81
7/49 - 90/81 is -61/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 49 and 81 is 3969
Next, find the equivalent fraction of both fractional numbers with denominator 3969 - For the 1st fraction, since 49 × 81 = 3969,
7/49 = 7 × 81/49 × 81 = 567/3969 - Likewise, for the 2nd fraction, since 81 × 49 = 3969,
90/81 = 90 × 49/81 × 49 = 4410/3969 - Subtract the two like fractions:
567/3969 - 4410/3969 = 567 - 4410/3969 = -3843/3969 - After reducing the fraction, the answer is -61/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/49-90/81 7/98-90/81 21/49-90/81 35/49-90/81