Subtract 20/21 from 10/18
10/18 - 20/21 is -25/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 18 and 21 is 126
Next, find the equivalent fraction of both fractional numbers with denominator 126 - For the 1st fraction, since 18 × 7 = 126,
10/18 = 10 × 7/18 × 7 = 70/126 - Likewise, for the 2nd fraction, since 21 × 6 = 126,
20/21 = 20 × 6/21 × 6 = 120/126 - Subtract the two like fractions:
70/126 - 120/126 = 70 - 120/126 = -50/126 - After reducing the fraction, the answer is -25/63
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