Add 18/81 and 21/80
18/81 + 21/80 is 349/720.
Steps for adding fractions
- Find the least common denominator or LCM of the two denominators:
LCM of 81 and 80 is 6480
Next, find the equivalent fraction of both fractional numbers with denominator 6480 - For the 1st fraction, since 81 × 80 = 6480,
18/81 = 18 × 80/81 × 80 = 1440/6480 - Likewise, for the 2nd fraction, since 80 × 81 = 6480,
21/80 = 21 × 81/80 × 81 = 1701/6480 - Add the two like fractions:
1440/6480 + 1701/6480 = 1440 + 1701/6480 = 3141/6480 - 3141/6480 simplified gives 349/720
- So, 18/81 + 21/80 = 349/720
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