Subtract 15/40 from 4/42
4/42 - 15/40 is -47/168.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
4/42 = 4 × 20/42 × 20 = 80/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
15/40 = 15 × 21/40 × 21 = 315/840 - Subtract the two like fractions:
80/840 - 315/840 = 80 - 315/840 = -235/840 - After reducing the fraction, the answer is -47/168
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 8/42-15/40 4/42-30/40 4/84-15/40 4/42-15/80 12/42-15/40 4/42-45/40 20/42-15/40 4/42-75/40 28/42-15/40