Subtract 20/25 from 18/42
18/42 - 20/25 is -13/35.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 25 is 1050
Next, find the equivalent fraction of both fractional numbers with denominator 1050 - For the 1st fraction, since 42 × 25 = 1050,
18/42 = 18 × 25/42 × 25 = 450/1050 - Likewise, for the 2nd fraction, since 25 × 42 = 1050,
20/25 = 20 × 42/25 × 42 = 840/1050 - Subtract the two like fractions:
450/1050 - 840/1050 = 450 - 840/1050 = -390/1050 - After reducing the fraction, the answer is -13/35
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