Subtract 12/21 from 21/70
21/70 - 12/21 is -19/70.
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,
21/70 = 21 × 3/70 × 3 = 63/210 - Likewise, for the 2nd fraction, since 21 × 10 = 210,
12/21 = 12 × 10/21 × 10 = 120/210 - Subtract the two like fractions:
63/210 - 120/210 = 63 - 120/210 = -57/210 - After reducing the fraction, the answer is -19/70
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