Subtract 21/15 from 20/42
1st number: 20/42, 2nd number: 1 6/15
20/42 - 21/15 is -97/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 42 and 15 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 42 × 5 = 210,
20/42 = 20 × 5/42 × 5 = 100/210 - Likewise, for the 2nd fraction, since 15 × 14 = 210,
21/15 = 21 × 14/15 × 14 = 294/210 - Subtract the two like fractions:
100/210 - 294/210 = 100 - 294/210 = -194/210 - After reducing the fraction, the answer is -97/105
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