Add 20/21 and 42/90
20/21 + 42/90 is 149/105.
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,
42/90 = 42 × 7/90 × 7 = 294/630 - Add the two like fractions:
600/630 + 294/630 = 600 + 294/630 = 894/630 - 894/630 simplified gives 149/105
- So, 20/21 + 42/90 = 149/105
In mixed form: 144/105
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