Subtract 15/5 from 18/21
1st number: 18/21, 2nd number: 3 0/5
18/21 - 15/5 is -15/7.
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,
18/21 = 18 × 5/21 × 5 = 90/105 - Likewise, for the 2nd fraction, since 5 × 21 = 105,
15/5 = 15 × 21/5 × 21 = 315/105 - Subtract the two like fractions:
90/105 - 315/105 = 90 - 315/105 = -225/105 - After reducing the fraction, the answer is -15/7
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