Subtract 18/90 from 21/2
1st number: 10 1/2, 2nd number: 18/90
21/2 - 18/90 is 103/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 2 and 90 is 90
Next, find the equivalent fraction of both fractional numbers with denominator 90 - For the 1st fraction, since 2 × 45 = 90,
21/2 = 21 × 45/2 × 45 = 945/90 - Likewise, for the 2nd fraction, since 90 × 1 = 90,
18/90 = 18 × 1/90 × 1 = 18/90 - Subtract the two like fractions:
945/90 - 18/90 = 945 - 18/90 = 927/90 - After reducing the fraction, the answer is 103/10
- In mixed form: 103/10
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 42/2-18/90 21/2-36/90 21/4-18/90 63/2-18/90 21/2-54/90 21/6-18/90 21/10-18/90 21/14-18/90