Subtract 3/9 from 5/21
5/21 - 3/9 is -2/21.
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,
5/21 = 5 × 3/21 × 3 = 15/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
3/9 = 3 × 7/9 × 7 = 21/63 - Subtract the two like fractions:
15/63 - 21/63 = 15 - 21/63 = -6/63 - After reducing the fraction, the answer is -2/21
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