Subtract 42/84 from 21/45
21/45 - 42/84 is -1/30.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 84 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 45 × 28 = 1260,
21/45 = 21 × 28/45 × 28 = 588/1260 - Likewise, for the 2nd fraction, since 84 × 15 = 1260,
42/84 = 42 × 15/84 × 15 = 630/1260 - Subtract the two like fractions:
588/1260 - 630/1260 = 588 - 630/1260 = -42/1260 - After reducing the fraction, the answer is -1/30
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