Subtract 21/25 from 7/90
7/90 - 21/25 is -343/450.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 25 is 450
Next, find the equivalent fraction of both fractional numbers with denominator 450 - For the 1st fraction, since 90 × 5 = 450,
7/90 = 7 × 5/90 × 5 = 35/450 - Likewise, for the 2nd fraction, since 25 × 18 = 450,
21/25 = 21 × 18/25 × 18 = 378/450 - Subtract the two like fractions:
35/450 - 378/450 = 35 - 378/450 = -343/450
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/90-21/25 7/90-42/25 7/90-21/50 21/90-21/25 7/90-63/25 7/90-21/75 35/90-21/25 49/90-21/25