Subtract 90/45 from 21/49
1st number: 21/49, 2nd number: 2 0/45
21/49 - 90/45 is -11/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 49 and 45 is 2205
Next, find the equivalent fraction of both fractional numbers with denominator 2205 - For the 1st fraction, since 49 × 45 = 2205,
21/49 = 21 × 45/49 × 45 = 945/2205 - Likewise, for the 2nd fraction, since 45 × 49 = 2205,
90/45 = 90 × 49/45 × 49 = 4410/2205 - Subtract the two like fractions:
945/2205 - 4410/2205 = 945 - 4410/2205 = -3465/2205 - After reducing the fraction, the answer is -11/7
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/49-90/45 21/98-90/45 63/49-90/45