Subtract 15/40 from 12/42
12/42 - 15/40 is -5/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 40 is 840
Next, find the equivalent fraction of both fractional numbers with denominator 840 - For the 1st fraction, since 42 × 20 = 840,
12/42 = 12 × 20/42 × 20 = 240/840 - Likewise, for the 2nd fraction, since 40 × 21 = 840,
15/40 = 15 × 21/40 × 21 = 315/840 - Subtract the two like fractions:
240/840 - 315/840 = 240 - 315/840 = -75/840 - After reducing the fraction, the answer is -5/56
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