Subtract 15/42 from 8/20
8/20 - 15/42 is 3/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 42 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
8/20 = 8 × 21/20 × 21 = 168/420 - Likewise, for the 2nd fraction, since 42 × 10 = 420,
15/42 = 15 × 10/42 × 10 = 150/420 - Subtract the two like fractions:
168/420 - 150/420 = 168 - 150/420 = 18/420 - After reducing the fraction, the answer is 3/70
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 16/20-15/42 8/20-30/42 8/40-15/42 8/20-15/84 24/20-15/42 8/20-45/42 8/60-15/42 40/20-15/42 8/20-75/42 56/20-15/42