Let's set x as the variable that has a solution of 2/3.
A possible equation is:
![1-x=y](https://img.qammunity.org/2023/formulas/mathematics/college/lxpq4zyz5u3nb9mh2bfv9yg6vfa5s8s5r8.png)
Now, in order to know the y-value, replace the x-value=2/3 and solve for y:
![\begin{gathered} 1-(2)/(3)=y \\ we\text{ can replace 1 by 1/1} \\ (1)/(1)-(2)/(3)=y \\ \text{The subtraction of fractions can be solved as} \\ (1*3-1*2)/(1*3)=y \\ (3-2)/(3)=y \\ (1)/(3)=y \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/z9i72jnlbsya0yi6nwcvss1bg2qih2iazw.png)
Now, replace the y-value in the initial equation, and we obtain:
![1-x=(1)/(3)](https://img.qammunity.org/2023/formulas/mathematics/college/8quvb55bwi2b0y60g8m4lawyu2zg736vp6.png)
If you solve this equation, you will get x=2/3.