Subtract 8/5 from 15/21
1st number: 15/21, 2nd number: 1 3/5
15/21 - 8/5 is -31/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 5 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
15/21 = 15 × 5/21 × 5 = 75/105 - Likewise, for the 2nd fraction, since 5 × 21 = 105,
8/5 = 8 × 21/5 × 21 = 168/105 - Subtract the two like fractions:
75/105 - 168/105 = 75 - 168/105 = -93/105 - After reducing the fraction, the answer is -31/35
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