Given the expression
[tex]6x-4y+7-3-8x+y+1+y[/tex]The first step is to order the like terms together.
That is the terms that have "x" go together, terms that have "y" form a second group and the constants form a third group:
[tex]6x-8x-4y+y+y+7-3+1[/tex]Then solve the operations between the like terms
[tex]\begin{gathered} (6x-8x)+(-4y+y+y)+(7-3+1) \\ -2x-2y+5 \end{gathered}[/tex]