Subtract 15/9 from 18/21
1st number: 18/21, 2nd number: 1 6/9
18/21 - 15/9 is -17/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 9 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 21 × 3 = 63,
18/21 = 18 × 3/21 × 3 = 54/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
15/9 = 15 × 7/9 × 7 = 105/63 - Subtract the two like fractions:
54/63 - 105/63 = 54 - 105/63 = -51/63 - After reducing the fraction, the answer is -17/21
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