Subtract 42/40 from 15/21
1st number: 15/21, 2nd number: 1 2/40
15/21 - 42/40 is -47/140.
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,
15/21 = 15 × 40/21 × 40 = 600/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
42/40 = 42 × 21/40 × 21 = 882/840 - Subtract the two like fractions:
600/840 - 882/840 = 600 - 882/840 = -282/840 - After reducing the fraction, the answer is -47/140
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