To find the distance \( d \) that Rina walked on Sunday, we can set up the following equation based on the information provided:
- The total distance Rina walked over the weekend is \( \frac{6}{5} \) km.
- The distance she walked on Saturday is \( \frac{2}{3} \) km.
Since the total distance is the sum of the distances walked on Saturday and Sunday, we can write the equation as:
\[ d + \frac{2}{3} = \frac{6}{5} \]
To solve for \( d \), we will first isolate \( d \):
\[ d = \frac{6}{5} - \frac{2}{3} \]
To subtract the fractions, we need a common denominator. The least common multiple of 5 and 3 is 15. We will convert both fractions:
\[ \frac{6}{5} = \frac{6 \times 3}{5 \times 3} = \frac{18}{15} \] \[ \frac{2}{3} = \frac{2 \times 5}{3 \times 5} = \frac{10}{15} \]
Now substituting these values back into the equation:
\[ d = \frac{18}{15} - \frac{10}{15} \] \[ d = \frac{8}{15} \]
So, Rina walked \( \frac{8}{15} \) km on Sunday.
In summary, the equation representing the distance that Rina walked on Sunday is:
\[ d + \frac{2}{3} = \frac{6}{5} \]
And the solution is \( d = \frac{8}{15} \) km.