Subtract 3/4 from 21/42
21/42 - 3/4 is -1/4.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 4 is 84
Next, find the equivalent fraction of both fractional numbers with denominator 84 - For the 1st fraction, since 42 × 2 = 84,
21/42 = 21 × 2/42 × 2 = 42/84 - Likewise, for the 2nd fraction, since 4 × 21 = 84,
3/4 = 3 × 21/4 × 21 = 63/84 - Subtract the two like fractions:
42/84 - 63/84 = 42 - 63/84 = -21/84 - After reducing the fraction, the answer is -1/4
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