Add 21/90 and 28/21
1st number: 21/90, 2nd number: 1 7/21
21/90 + 28/21 is 47/30.
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,
21/90 = 21 × 7/90 × 7 = 147/630 - Likewise, for the 2nd fraction, since 21 × 30 = 630,
28/21 = 28 × 30/21 × 30 = 840/630 - Add the two like fractions:
147/630 + 840/630 = 147 + 840/630 = 987/630 - 987/630 simplified gives 47/30
- So, 21/90 + 28/21 = 47/30
In mixed form: 117/30
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