Question 3
We only have to put a different number to one, since this makes that equality is not maintained and the expression has no solution
![\begin{gathered} 3x+1=3x+2 \\ \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/5ztoa3namc77fz15mkn31tqdvsk0a33yax.png)
checking
![\begin{gathered} 3x-3x=2-1 \\ 0=1 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/wqrb9lkz2iifodvbn7qnmykili0hdy3a3s.png)
equality is wrong
Question 4
in this case we want the expression to have a solution for any value of x, so equality must be preserved and x must disappear or not matter in the expression
![2x-4=2x-4](https://img.qammunity.org/2023/formulas/mathematics/college/3h3sqzjx4k2fn92arns3wu5nwifjb8gmjz.png)
cheking
![\begin{gathered} 2x-2x=-4+4 \\ 0=0 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/nitwt3sgjiilrbvsht19v74f45mpdoythv.png)
equality is correct and does not interfere, so it can take any value