Subtract 15/18 from 5/21
5/21 - 15/18 is -25/42.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 18 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 21 × 6 = 126,
5/21 = 5 × 6/21 × 6 = 30/126 - Likewise, for the 2nd fraction, since 18 × 7 = 126,
15/18 = 15 × 7/18 × 7 = 105/126 - Subtract the two like fractions:
30/126 - 105/126 = 30 - 105/126 = -75/126 - After reducing the fraction, the answer is -25/42
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