Add 20/21 and 28/90
20/21 + 28/90 is 398/315.
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,
20/21 = 20 × 30/21 × 30 = 600/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
28/90 = 28 × 7/90 × 7 = 196/630 - Add the two like fractions:
600/630 + 196/630 = 600 + 196/630 = 796/630 - 796/630 simplified gives 398/315
- So, 20/21 + 28/90 = 398/315
In mixed form: 183/315
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