Subtract 20/70 from 7/42
7/42 - 20/70 is -5/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 70 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
7/42 = 7 × 5/42 × 5 = 35/210 - Likewise, for the 2nd fraction, since 70 × 3 = 210,
20/70 = 20 × 3/70 × 3 = 60/210 - Subtract the two like fractions:
35/210 - 60/210 = 35 - 60/210 = -25/210 - After reducing the fraction, the answer is -5/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 14/42-20/70 7/42-40/70 7/84-20/70 21/42-20/70 7/42-60/70 35/42-20/70 49/42-20/70