Subtract 21/40 from 21/2
1st number: 10 1/2, 2nd number: 21/40
21/2 - 21/40 is 399/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 2 and 40 is 40
Next, find the equivalent fraction of both fractional numbers with denominator 40 - For the 1st fraction, since 2 × 20 = 40,
21/2 = 21 × 20/2 × 20 = 420/40 - Likewise, for the 2nd fraction, since 40 × 1 = 40,
21/40 = 21 × 1/40 × 1 = 21/40 - Subtract the two like fractions:
420/40 - 21/40 = 420 - 21/40 = 399/40 - In mixed form: 939/40
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