Subtract 12/21 from 21/90
21/90 - 12/21 is -71/210.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 21 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 90 × 7 = 630,
21/90 = 21 × 7/90 × 7 = 147/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
12/21 = 12 × 30/21 × 30 = 360/630 - Subtract the two like fractions:
147/630 - 360/630 = 147 - 360/630 = -213/630 - After reducing the fraction, the answer is -71/210
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