Subtract 1/80 from 21/42
21/42 - 1/80 is 39/80.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 42 × 40 = 1680,
21/42 = 21 × 40/42 × 40 = 840/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
1/80 = 1 × 21/80 × 21 = 21/1680 - Subtract the two like fractions:
840/1680 - 21/1680 = 840 - 21/1680 = 819/1680 - After reducing the fraction, the answer is 39/80
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