Subtract 5/7 from 81/90
81/90 - 5/7 is 13/70.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 7 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
81/90 = 81 × 7/90 × 7 = 567/630 - Likewise, for the 2nd fraction, since 7 × 90 = 630,
5/7 = 5 × 90/7 × 90 = 450/630 - Subtract the two like fractions:
567/630 - 450/630 = 567 - 450/630 = 117/630 - After reducing the fraction, the answer is 13/70
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