You can operate just similar terms, similar terms in the given equation are:
10x and 3x
5 and -2
Then, you get:
[tex]\begin{gathered} =(10x+3x)+(5-2) \\ =13x+3 \end{gathered}[/tex]-------------------------------------
[tex]4-2x+5x[/tex]Similar terms:
-2x and 5x
[tex]\begin{gathered} =4+(-2x+5x) \\ =4+3x \end{gathered}[/tex]