Subtract 90/80 from 12/21
1st number: 12/21, 2nd number: 1 10/80
12/21 - 90/80 is -31/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 80 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 21 × 80 = 1680,
12/21 = 12 × 80/21 × 80 = 960/1680 - Likewise, for the 2nd fraction, since 80 × 21 = 1680,
90/80 = 90 × 21/80 × 21 = 1890/1680 - Subtract the two like fractions:
960/1680 - 1890/1680 = 960 - 1890/1680 = -930/1680 - After reducing the fraction, the answer is -31/56
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