Subtract 15/7 from 21/90
1st number: 21/90, 2nd number: 2 1/7
21/90 - 15/7 is -401/210.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 90 and 7 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 7 × 90 = 630,
15/7 = 15 × 90/7 × 90 = 1350/630 - Subtract the two like fractions:
147/630 - 1350/630 = 147 - 1350/630 = -1203/630 - After reducing the fraction, the answer is -401/210
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