Subtract 20/42 from 63/81
63/81 - 20/42 is 19/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 42 is 1134
Next, find the equivalent fraction of both fractional numbers with denominator 1134 - For the 1st fraction, since 81 × 14 = 1134,
63/81 = 63 × 14/81 × 14 = 882/1134 - Likewise, for the 2nd fraction, since 42 × 27 = 1134,
20/42 = 20 × 27/42 × 27 = 540/1134 - Subtract the two like fractions:
882/1134 - 540/1134 = 882 - 540/1134 = 342/1134 - After reducing the fraction, the answer is 19/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 63/81-40/42 63/81-20/84 63/81-60/42