Subtract 3/40 from 42/70
42/70 - 3/40 is 21/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 40 is 280
Next, find the equivalent fraction of both fractional numbers with denominator 280 - For the 1st fraction, since 70 × 4 = 280,
42/70 = 42 × 4/70 × 4 = 168/280 - Likewise, for the 2nd fraction, since 40 × 7 = 280,
3/40 = 3 × 7/40 × 7 = 21/280 - Subtract the two like fractions:
168/280 - 21/280 = 168 - 21/280 = 147/280 - After reducing the fraction, the answer is 21/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/70-3/40 42/70-6/40 42/70-3/80 42/70-9/40 42/70-15/40 42/70-21/40