Subtract 45/21 from 18/20
1st number: 18/20, 2nd number: 2 3/21
18/20 - 45/21 is -87/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 20 and 21 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 20 × 21 = 420,
18/20 = 18 × 21/20 × 21 = 378/420 - Likewise, for the 2nd fraction, since 21 × 20 = 420,
45/21 = 45 × 20/21 × 20 = 900/420 - Subtract the two like fractions:
378/420 - 900/420 = 378 - 900/420 = -522/420 - After reducing the fraction, the answer is -87/70
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