Subtract 81/84 from 72/90
72/90 - 81/84 is -23/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 84 is 1260
Next, find the equivalent fraction of both fractional numbers with denominator 1260 - For the 1st fraction, since 90 × 14 = 1260,
72/90 = 72 × 14/90 × 14 = 1008/1260 - Likewise, for the 2nd fraction, since 84 × 15 = 1260,
81/84 = 81 × 15/84 × 15 = 1215/1260 - Subtract the two like fractions:
1008/1260 - 1215/1260 = 1008 - 1215/1260 = -207/1260 - After reducing the fraction, the answer is -23/140
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