In order to find the missing value, we need to subtract 1x from each side of the first equation.
Doing that, we have:
![\begin{gathered} 3x+2=x+28 \\ 3x+2-x=x+28-x \\ (3x-x)+2=28 \\ 2x+2=28 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/3vunvx7cy6bhe9ezberqlp2hsd8ilwxznp.png)
Comparing the equation 2x + 2 = 28 with the second equation where we have the missing value, we can see that the missing value is equal to 2.