Subtract 42/84 from 3/30
3/30 - 42/84 is -2/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 84 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 30 × 14 = 420,
3/30 = 3 × 14/30 × 14 = 42/420 - Likewise, for the 2nd fraction, since 84 × 5 = 420,
42/84 = 42 × 5/84 × 5 = 210/420 - Subtract the two like fractions:
42/420 - 210/420 = 42 - 210/420 = -168/420 - After reducing the fraction, the answer is -2/5
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 6/30-42/84 3/60-42/84 9/30-42/84 3/90-42/84 15/30-42/84 21/30-42/84