Add 81/21 and 20/90
1st number: 3 18/21, 2nd number: 20/90
81/21 + 20/90 is 257/63.
Steps for adding 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,
81/21 = 81 × 30/21 × 30 = 2430/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
20/90 = 20 × 7/90 × 7 = 140/630 - Add the two like fractions:
2430/630 + 140/630 = 2430 + 140/630 = 2570/630 - 2570/630 simplified gives 257/63
- So, 81/21 + 20/90 = 257/63
In mixed form: 45/63
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