Subtract 3/21 from 7/9
7/9 - 3/21 is 40/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 9 and 21 is 63
Next, find the equivalent fraction of both fractional numbers with denominator 63 - For the 1st fraction, since 9 × 7 = 63,
7/9 = 7 × 7/9 × 7 = 49/63 - Likewise, for the 2nd fraction, since 21 × 3 = 63,
3/21 = 3 × 3/21 × 3 = 9/63 - Subtract the two like fractions:
49/63 - 9/63 = 49 - 9/63 = 40/63
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