Subtract 12/90 from 9/21
9/21 - 12/90 is 31/105.
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,
9/21 = 9 × 30/21 × 30 = 270/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
12/90 = 12 × 7/90 × 7 = 84/630 - Subtract the two like fractions:
270/630 - 84/630 = 270 - 84/630 = 186/630 - After reducing the fraction, the answer is 31/105
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