Subtract 80/90 from 15/21
15/21 - 80/90 is -11/63.
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,
15/21 = 15 × 30/21 × 30 = 450/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
80/90 = 80 × 7/90 × 7 = 560/630 - Subtract the two like fractions:
450/630 - 560/630 = 450 - 560/630 = -110/630 - After reducing the fraction, the answer is -11/63
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