Subtract 18/9 from 20/21
1st number: 20/21, 2nd number: 2 0/9
20/21 - 18/9 is -22/21.
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,
20/21 = 20 × 3/21 × 3 = 60/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
18/9 = 18 × 7/9 × 7 = 126/63 - Subtract the two like fractions:
60/63 - 126/63 = 60 - 126/63 = -66/63 - After reducing the fraction, the answer is -22/21
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