Add 18/21 and 15/90
18/21 + 15/90 is 43/42.
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,
15/90 = 15 × 7/90 × 7 = 105/630 - Add the two like fractions:
540/630 + 105/630 = 540 + 105/630 = 645/630 - 645/630 simplified gives 43/42
- So, 18/21 + 15/90 = 43/42
In mixed form: 11/42
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