Subtract 10/90 from 8/21
8/21 - 10/90 is 17/63.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 21 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 21 × 30 = 630,
8/21 = 8 × 30/21 × 30 = 240/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
10/90 = 10 × 7/90 × 7 = 70/630 - Subtract the two like fractions:
240/630 - 70/630 = 240 - 70/630 = 170/630 - After reducing the fraction, the answer is 17/63
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