Subtract 7/40 from 15/42
15/42 - 7/40 is 51/280.
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,
15/42 = 15 × 20/42 × 20 = 300/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
7/40 = 7 × 21/40 × 21 = 147/840 - Subtract the two like fractions:
300/840 - 147/840 = 300 - 147/840 = 153/840 - After reducing the fraction, the answer is 51/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 30/42-7/40 15/42-14/40 15/84-7/40 15/42-7/80 45/42-7/40 15/42-21/40 75/42-7/40 15/42-35/40 15/42-49/40