Subtract 1/20 from 12/42
12/42 - 1/20 is 33/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 20 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 42 × 10 = 420,
12/42 = 12 × 10/42 × 10 = 120/420 - Likewise, for the 2nd fraction, since 20 × 21 = 420,
1/20 = 1 × 21/20 × 21 = 21/420 - Subtract the two like fractions:
120/420 - 21/420 = 120 - 21/420 = 99/420 - After reducing the fraction, the answer is 33/140
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