Subtract 90/42 from 21/4
1st number: 5 1/4, 2nd number: 2 6/42
21/4 - 90/42 is 87/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 42 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 4 × 21 = 84,
21/4 = 21 × 21/4 × 21 = 441/84 - Likewise, for the 2nd fraction, since 42 × 2 = 84,
90/42 = 90 × 2/42 × 2 = 180/84 - Subtract the two like fractions:
441/84 - 180/84 = 441 - 180/84 = 261/84 - After reducing the fraction, the answer is 87/28
- In mixed form: 33/28
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/4-90/42 21/8-90/42 21/4-90/84 63/4-90/42 21/12-90/42 21/20-90/42 21/28-90/42