Subtract 8/18 from 16/21
16/21 - 8/18 is 20/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
16/21 = 16 × 6/21 × 6 = 96/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
8/18 = 8 × 7/18 × 7 = 56/126 - Subtract the two like fractions:
96/126 - 56/126 = 96 - 56/126 = 40/126 - After reducing the fraction, the answer is 20/63
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 32/21-8/18 16/21-16/18 16/42-8/18 16/21-8/36 48/21-8/18 16/21-24/18 16/63-8/18 16/21-8/54 80/21-8/18 16/21-40/18 16/21-8/90 16/21-56/18