Subtract 40/42 from 81/21
1st number: 3 18/21, 2nd number: 40/42
81/21 - 40/42 is 61/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 42 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 21 × 2 = 42,
81/21 = 81 × 2/21 × 2 = 162/42 - Likewise, for the 2nd fraction, since 42 × 1 = 42,
40/42 = 40 × 1/42 × 1 = 40/42 - Subtract the two like fractions:
162/42 - 40/42 = 162 - 40/42 = 122/42 - After reducing the fraction, the answer is 61/21
- In mixed form: 219/21
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