Subtract 18/10 from 20/21
1st number: 20/21, 2nd number: 1 8/10
20/21 - 18/10 is -89/105.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 10 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 21 × 10 = 210,
20/21 = 20 × 10/21 × 10 = 200/210 - Likewise, for the 2nd fraction, since 10 × 21 = 210,
18/10 = 18 × 21/10 × 21 = 378/210 - Subtract the two like fractions:
200/210 - 378/210 = 200 - 378/210 = -178/210 - After reducing the fraction, the answer is -89/105
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