Subtract 42/49 from 6/21
6/21 - 42/49 is -4/7.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 49 is 147
Next, find the equivalent fraction of both fractional numbers with denominator 147 - For the 1st fraction, since 21 × 7 = 147,
6/21 = 6 × 7/21 × 7 = 42/147 - Likewise, for the 2nd fraction, since 49 × 3 = 147,
42/49 = 42 × 3/49 × 3 = 126/147 - Subtract the two like fractions:
42/147 - 126/147 = 42 - 126/147 = -84/147 - After reducing the fraction, the answer is -4/7
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