Subtract 24/21 from 42/45
1st number: 42/45, 2nd number: 1 3/21
42/45 - 24/21 is -22/105.
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,
42/45 = 42 × 7/45 × 7 = 294/315 - Likewise, for the 2nd fraction, since 21 × 15 = 315,
24/21 = 24 × 15/21 × 15 = 360/315 - Subtract the two like fractions:
294/315 - 360/315 = 294 - 360/315 = -66/315 - After reducing the fraction, the answer is -22/105
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/45-24/21 42/45-48/21 42/90-24/21 42/45-24/42 42/45-72/21 42/45-24/63