Subtract 40/20 from 18/21
1st number: 18/21, 2nd number: 2 0/20
18/21 - 40/20 is -8/7.
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,
40/20 = 40 × 21/20 × 21 = 840/420 - Subtract the two like fractions:
360/420 - 840/420 = 360 - 840/420 = -480/420 - After reducing the fraction, the answer is -8/7
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