Subtract 1/21 from 45/70
45/70 - 1/21 is 25/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
45/70 = 45 × 3/70 × 3 = 135/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
1/21 = 1 × 10/21 × 10 = 10/210 - Subtract the two like fractions:
135/210 - 10/210 = 135 - 10/210 = 125/210 - After reducing the fraction, the answer is 25/42
MathStep (Works offline)
Download our mobile app and learn to work with fractions in your own time:
Android and iPhone/ iPad
Related: 90/70-1/21 45/70-2/21 45/70-1/42 45/70-3/21 45/70-1/63 45/70-5/21 45/70-7/21