Subtract 5/20 from 18/21
18/21 - 5/20 is 17/28.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 21 × 20 = 420,
18/21 = 18 × 20/21 × 20 = 360/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
5/20 = 5 × 21/20 × 21 = 105/420 - Subtract the two like fractions:
360/420 - 105/420 = 360 - 105/420 = 255/420 - After reducing the fraction, the answer is 17/28
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