Subtract 12/40 from 42/21
1st number: 2 0/21, 2nd number: 12/40
42/21 - 12/40 is 17/10.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 21 × 40 = 840,
42/21 = 42 × 40/21 × 40 = 1680/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
12/40 = 12 × 21/40 × 21 = 252/840 - Subtract the two like fractions:
1680/840 - 252/840 = 1680 - 252/840 = 1428/840 - After reducing the fraction, the answer is 17/10
- In mixed form: 17/10
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