Subtract 42/21 from 5/40
1st number: 5/40, 2nd number: 2 0/21
5/40 - 42/21 is -15/8.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 40 and 21 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 40 × 21 = 840,
5/40 = 5 × 21/40 × 21 = 105/840 - Likewise, for the 2nd fraction, since 21 × 40 = 840,
42/21 = 42 × 40/21 × 40 = 1680/840 - Subtract the two like fractions:
105/840 - 1680/840 = 105 - 1680/840 = -1575/840 - After reducing the fraction, the answer is -15/8
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