Subtract 21/9 from 42/21
1st number: 2 0/21, 2nd number: 2 3/9
42/21 - 21/9 is -1/3.
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,
42/21 = 42 × 3/21 × 3 = 126/63 - Likewise, for the 2nd fraction, since 9 × 7 = 63,
21/9 = 21 × 7/9 × 7 = 147/63 - Subtract the two like fractions:
126/63 - 147/63 = 126 - 147/63 = -21/63 - After reducing the fraction, the answer is -1/3
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