Subtract 21/40 from 81/4
1st number: 20 1/4, 2nd number: 21/40
81/4 - 21/40 is 789/40.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 4 and 40 is 40
Next, find the equivalent fraction of both fractional numbers with denominator 40 - For the 1st fraction, since 4 × 10 = 40,
81/4 = 81 × 10/4 × 10 = 810/40 - Likewise, for the 2nd fraction, since 40 × 1 = 40,
21/40 = 21 × 1/40 × 1 = 21/40 - Subtract the two like fractions:
810/40 - 21/40 = 810 - 21/40 = 789/40 - In mixed form: 1929/40
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