Subtract 30/15 from 18/21
1st number: 18/21, 2nd number: 2 0/15
18/21 - 30/15 is -8/7.
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,
18/21 = 18 × 5/21 × 5 = 90/105 - Likewise, for the 2nd fraction, since 15 × 7 = 105,
30/15 = 30 × 7/15 × 7 = 210/105 - Subtract the two like fractions:
90/105 - 210/105 = 90 - 210/105 = -120/105 - After reducing the fraction, the answer is -8/7
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