In order to simplify this, you need to combine like terms. "Like terms" are numbers with the same variable. When you add them, you just need to add the value of the coefficients.
[tex]-4c+7-2k+5c+6k+c-3+c[/tex]
First, reorder them so that the common variables are together and it is easier to solve.
[tex]-4c+5c+c+c-2k+6k+7-3 \\ \\ (-4+5+1+1)c+(-2+6)k+(7-3) \\ \\ 3c+4k+4[/tex]
