Subtract 21/15 from 81/21
1st number: 3 18/21, 2nd number: 1 6/15
81/21 - 21/15 is 86/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 15 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
81/21 = 81 × 5/21 × 5 = 405/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
21/15 = 21 × 7/15 × 7 = 147/105 - Subtract the two like fractions:
405/105 - 147/105 = 405 - 147/105 = 258/105 - After reducing the fraction, the answer is 86/35
- In mixed form: 216/35
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