Add 18/21 and 20/90
18/21 + 20/90 is 68/63.
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,
18/21 = 18 × 30/21 × 30 = 540/630 - Likewise, for the 2nd fraction, since 90 × 7 = 630,
20/90 = 20 × 7/90 × 7 = 140/630 - Add the two like fractions:
540/630 + 140/630 = 540 + 140/630 = 680/630 - 680/630 simplified gives 68/63
- So, 18/21 + 20/90 = 68/63
In mixed form: 15/63
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