Subtract 42/80 from 7/20
7/20 - 42/80 is -7/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 80 is 80
Next, find the equivalent fraction of both fractional numbers with denominator 80 - For the 1st fraction, since 20 × 4 = 80,
7/20 = 7 × 4/20 × 4 = 28/80 - Likewise, for the 2nd fraction, since 80 × 1 = 80,
42/80 = 42 × 1/80 × 1 = 42/80 - Subtract the two like fractions:
28/80 - 42/80 = 28 - 42/80 = -14/80 - After reducing the fraction, the answer is -7/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/20-42/80 7/20-84/80 7/40-42/80 21/20-42/80 7/60-42/80 35/20-42/80 49/20-42/80