Subtract 15/16 from 21/45
21/45 - 15/16 is -113/240.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 16 is 720
Next, find the equivalent fraction of both fractional numbers with denominator 720 - For the 1st fraction, since 45 × 16 = 720,
21/45 = 21 × 16/45 × 16 = 336/720 - Likewise, for the 2nd fraction, since 16 × 45 = 720,
15/16 = 15 × 45/16 × 45 = 675/720 - Subtract the two like fractions:
336/720 - 675/720 = 336 - 675/720 = -339/720 - After reducing the fraction, the answer is -113/240
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/45-15/16 21/45-30/16 21/90-15/16 21/45-15/32 63/45-15/16 21/45-45/16 21/45-15/48 21/45-75/16 21/45-15/80