Subtract 20/8 from 70/42
1st number: 1 28/42, 2nd number: 2 4/8
70/42 - 20/8 is -5/6.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 8 is 168
Next, find the equivalent fraction of both fractional numbers with denominator 168 - For the 1st fraction, since 42 × 4 = 168,
70/42 = 70 × 4/42 × 4 = 280/168 - Likewise, for the 2nd fraction, since 8 × 21 = 168,
20/8 = 20 × 21/8 × 21 = 420/168 - Subtract the two like fractions:
280/168 - 420/168 = 280 - 420/168 = -140/168 - After reducing the fraction, the answer is -5/6
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 70/42-40/8 70/84-20/8 70/42-20/16 70/42-60/8 70/42-20/24 70/42-20/40 70/42-20/56