Subtract 72/21 from 90/80
1st number: 1 10/80, 2nd number: 3 9/21
90/80 - 72/21 is -129/56.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 80 and 21 is 1680
Next, find the equivalent fraction of both fractional numbers with denominator 1680 - For the 1st fraction, since 80 × 21 = 1680,
90/80 = 90 × 21/80 × 21 = 1890/1680 - Likewise, for the 2nd fraction, since 21 × 80 = 1680,
72/21 = 72 × 80/21 × 80 = 5760/1680 - Subtract the two like fractions:
1890/1680 - 5760/1680 = 1890 - 5760/1680 = -3870/1680 - After reducing the fraction, the answer is -129/56
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