Consider the given expression,
[tex](6k+5)-(2k+5)[/tex]Eliminate the parenthesis,
[tex]6k+5-2k-5[/tex]Note that only the like terms can be added.
So the expression becomes,
[tex]\begin{gathered} (6k-2k)+(5-5) \\ 4k+0 \\ 4k \end{gathered}[/tex]Thus, the subtraction gives,
[tex](6k+5)-(2k+5)=4k[/tex]