Subtract 72/90 from 10/21
10/21 - 72/90 is -34/105.
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,
10/21 = 10 × 30/21 × 30 = 300/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
72/90 = 72 × 7/90 × 7 = 504/630 - Subtract the two like fractions:
300/630 - 504/630 = 300 - 504/630 = -204/630 - After reducing the fraction, the answer is -34/105
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