Subtract 21/7 from 18/42
1st number: 18/42, 2nd number: 3 0/7
18/42 - 21/7 is -18/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 7 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 7 × 6 = 42,
21/7 = 21 × 6/7 × 6 = 126/42 - Subtract the two like fractions:
18/42 - 126/42 = 18 - 126/42 = -108/42 - After reducing the fraction, the answer is -18/7
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