Subtract 4/21 from 3/45
3/45 - 4/21 is -13/105.
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,
3/45 = 3 × 7/45 × 7 = 21/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
4/21 = 4 × 15/21 × 15 = 60/315 - Subtract the two like fractions:
21/315 - 60/315 = 21 - 60/315 = -39/315 - After reducing the fraction, the answer is -13/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/45-4/21 3/45-8/21 3/90-4/21 3/45-4/42 9/45-4/21 3/45-12/21 3/45-4/63 15/45-4/21 3/45-20/21 21/45-4/21 3/45-28/21