Subtract 8/9 from 21/84
21/84 - 8/9 is -23/36.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 84 and 9 is 252
Next, find the equivalent fraction of both fractional numbers with denominator 252 - For the 1st fraction, since 84 × 3 = 252,
21/84 = 21 × 3/84 × 3 = 63/252 - Likewise, for the 2nd fraction, since 9 × 28 = 252,
8/9 = 8 × 28/9 × 28 = 224/252 - Subtract the two like fractions:
63/252 - 224/252 = 63 - 224/252 = -161/252 - After reducing the fraction, the answer is -23/36
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/84-8/9 21/84-16/9 21/84-8/18 63/84-8/9 21/84-24/9 21/84-8/27 21/84-40/9 21/84-8/45 21/84-56/9 21/84-8/63