Subtract 28/40 from 6/21
6/21 - 28/40 is -29/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
6/21 = 6 × 40/21 × 40 = 240/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
28/40 = 28 × 21/40 × 21 = 588/840 - Subtract the two like fractions:
240/840 - 588/840 = 240 - 588/840 = -348/840 - After reducing the fraction, the answer is -29/70
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