Subtract 40/72 from 15/42
15/42 - 40/72 is -25/126.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 72 is 504
Next, find the equivalent fraction of both fractional numbers with denominator 504 - For the 1st fraction, since 42 × 12 = 504,
15/42 = 15 × 12/42 × 12 = 180/504 - Likewise, for the 2nd fraction, since 72 × 7 = 504,
40/72 = 40 × 7/72 × 7 = 280/504 - Subtract the two like fractions:
180/504 - 280/504 = 180 - 280/504 = -100/504 - After reducing the fraction, the answer is -25/126
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