Subtract 28/90 from 21/7
1st number: 3 0/7, 2nd number: 28/90
21/7 - 28/90 is 121/45.
Steps for subtracting fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 7 and 90 is 630
Next, find the equivalent fraction of both fractional numbers with denominator 630 - For the 1st fraction, since 7 × 90 = 630,
21/7 = 21 × 90/7 × 90 = 1890/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
28/90 = 28 × 7/90 × 7 = 196/630 - Subtract the two like fractions:
1890/630 - 196/630 = 1890 - 196/630 = 1694/630 - After reducing the fraction, the answer is 121/45
- In mixed form: 231/45
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