Subtract 81/21 from 28/40
1st number: 28/40, 2nd number: 3 18/21
28/40 - 81/21 is -221/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
28/40 = 28 × 21/40 × 21 = 588/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
81/21 = 81 × 40/21 × 40 = 3240/840 - Subtract the two like fractions:
588/840 - 3240/840 = 588 - 3240/840 = -2652/840 - After reducing the fraction, the answer is -221/70
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