Subtract 21/84 from 18/70
18/70 - 21/84 is 1/140.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 84 is 420
Next, find the equivalent fraction of both fractional numbers with denominator 420 - For the 1st fraction, since 70 × 6 = 420,
18/70 = 18 × 6/70 × 6 = 108/420 - Likewise, for the 2nd fraction, since 84 × 5 = 420,
21/84 = 21 × 5/84 × 5 = 105/420 - Subtract the two like fractions:
108/420 - 105/420 = 108 - 105/420 = 3/420 - After reducing the fraction, the answer is 1/140
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