Subtract 10/21 from 20/70
20/70 - 10/21 is -4/21.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 21 is 210
Next, find the equivalent fraction of both fractional numbers with denominator 210 - For the 1st fraction, since 70 × 3 = 210,
20/70 = 20 × 3/70 × 3 = 60/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
10/21 = 10 × 10/21 × 10 = 100/210 - Subtract the two like fractions:
60/210 - 100/210 = 60 - 100/210 = -40/210 - After reducing the fraction, the answer is -4/21
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