Subtract 5/42 from 21/80
21/80 - 5/42 is 241/1680.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 42 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
21/80 = 21 × 21/80 × 21 = 441/1680 - Likewise, for the 2nd fraction, since 42 × 40 = 1680,
5/42 = 5 × 40/42 × 40 = 200/1680 - Subtract the two like fractions:
441/1680 - 200/1680 = 441 - 200/1680 = 241/1680
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/80-5/42 21/80-10/42 21/80-5/84 63/80-5/42 21/80-15/42 21/80-25/42 21/80-35/42