Subtract 8/12 from 21/45
21/45 - 8/12 is -1/5.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 45 and 12 is 180
Next, find the equivalent fraction of both fractional numbers with denominator 180 - For the 1st fraction, since 45 × 4 = 180,
21/45 = 21 × 4/45 × 4 = 84/180 - Likewise, for the 2nd fraction, since 12 × 15 = 180,
8/12 = 8 × 15/12 × 15 = 120/180 - Subtract the two like fractions:
84/180 - 120/180 = 84 - 120/180 = -36/180 - After reducing the fraction, the answer is -1/5
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