Subtract 81/84 from 42/80
42/80 - 81/84 is -123/280.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 84 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
42/80 = 42 × 21/80 × 21 = 882/1680 - Likewise, for the 2nd fraction, since 84 × 20 = 1680,
81/84 = 81 × 20/84 × 20 = 1620/1680 - Subtract the two like fractions:
882/1680 - 1620/1680 = 882 - 1620/1680 = -738/1680 - After reducing the fraction, the answer is -123/280
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Related: 84/80-81/84