Subtract 42/80 from 9/21
9/21 - 42/80 is -27/280.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 21 × 80 = 1680,
9/21 = 9 × 80/21 × 80 = 720/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
42/80 = 42 × 21/80 × 21 = 882/1680 - Subtract the two like fractions:
720/1680 - 882/1680 = 720 - 882/1680 = -162/1680 - After reducing the fraction, the answer is -27/280
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 18/21-42/80 9/21-84/80 9/42-42/80 27/21-42/80 9/63-42/80 45/21-42/80 63/21-42/80