Subtract 21/81 from 90/70
1st number: 1 20/70, 2nd number: 21/81
90/70 - 21/81 is 194/189.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 70 and 81 is 5670
Next, find the equivalent fraction of both fractional numbers with denominator 5670 - For the 1st fraction, since 70 × 81 = 5670,
90/70 = 90 × 81/70 × 81 = 7290/5670 - Likewise, for the 2nd fraction, since 81 × 70 = 5670,
21/81 = 21 × 70/81 × 70 = 1470/5670 - Subtract the two like fractions:
7290/5670 - 1470/5670 = 7290 - 1470/5670 = 5820/5670 - After reducing the fraction, the answer is 194/189
- In mixed form: 15/189
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