Subtract 18/5 from 42/21
1st number: 2 0/21, 2nd number: 3 3/5
42/21 - 18/5 is -8/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 5 is 105
Next, find the equivalent fraction of both fractional numbers with denominator 105 - For the 1st fraction, since 21 × 5 = 105,
42/21 = 42 × 5/21 × 5 = 210/105 - Likewise, for the 2nd fraction, since 5 × 21 = 105,
18/5 = 18 × 21/5 × 21 = 378/105 - Subtract the two like fractions:
210/105 - 378/105 = 210 - 378/105 = -168/105 - After reducing the fraction, the answer is -8/5
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