Subtract 8/21 from 4/45
4/45 - 8/21 is -92/315.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 21 is 315
Next, find the equivalent fraction of both fractional numbers with denominator 315 - For the 1st fraction, since 45 × 7 = 315,
4/45 = 4 × 7/45 × 7 = 28/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
8/21 = 8 × 15/21 × 15 = 120/315 - Subtract the two like fractions:
28/315 - 120/315 = 28 - 120/315 = -92/315
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/45-8/21 4/45-16/21 4/90-8/21 4/45-8/42 12/45-8/21 4/45-24/21 4/45-8/63 20/45-8/21 4/45-40/21 28/45-8/21 4/45-56/21