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