Subtract 28/21 from 18/42
1st number: 18/42, 2nd number: 1 7/21
18/42 - 28/21 is -19/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 21 is 42
Next, find the equivalent fraction of both fractional numbers with denominator 42 - For the 1st fraction, since 42 × 1 = 42,
18/42 = 18 × 1/42 × 1 = 18/42 - Likewise, for the 2nd fraction, since 21 × 2 = 42,
28/21 = 28 × 2/21 × 2 = 56/42 - Subtract the two like fractions:
18/42 - 56/42 = 18 - 56/42 = -38/42 - After reducing the fraction, the answer is -19/21
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