Subtract 18/80 from 21/30
21/30 - 18/80 is 19/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 30 and 80 is 240
Next, find the equivalent fraction of both fractional numbers with denominator 240 - For the 1st fraction, since 30 × 8 = 240,
21/30 = 21 × 8/30 × 8 = 168/240 - Likewise, for the 2nd fraction, since 80 × 3 = 240,
18/80 = 18 × 3/80 × 3 = 54/240 - Subtract the two like fractions:
168/240 - 54/240 = 168 - 54/240 = 114/240 - After reducing the fraction, the answer is 19/40
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/30-18/80 21/30-36/80 21/60-18/80 63/30-18/80 21/30-54/80 21/90-18/80 21/30-90/80