Subtract 7/40 from 42/80
42/80 - 7/40 is 7/20.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 40 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 80 × 1 = 80,
42/80 = 42 × 1/80 × 1 = 42/80 - Likewise, for the 2nd fraction, since 40 × 2 = 80,
7/40 = 7 × 2/40 × 2 = 14/80 - Subtract the two like fractions:
42/80 - 14/80 = 42 - 14/80 = 28/80 - After reducing the fraction, the answer is 7/20
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 84/80-7/40 42/80-14/40 42/80-7/80 42/80-21/40 42/80-35/40 42/80-49/40