Subtract 18/27 from 21/30
21/30 - 18/27 is 1/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 27 is 270
Next, find the equivalent fraction of both fractional numbers with denominator 270 - For the 1st fraction, since 30 × 9 = 270,
21/30 = 21 × 9/30 × 9 = 189/270 - Likewise, for the 2nd fraction, since 27 × 10 = 270,
18/27 = 18 × 10/27 × 10 = 180/270 - Subtract the two like fractions:
189/270 - 180/270 = 189 - 180/270 = 9/270 - After reducing the fraction, the answer is 1/30
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30-18/27 21/30-36/27 21/60-18/27 21/30-18/54 63/30-18/27 21/30-54/27 21/90-18/27 21/30-18/81 21/30-90/27