I guess it is simplifying the expression:
[tex]{ \tt{94 - x - 67 - x}} \\ = { \tt{94 - 67 + ( - x - x)}} \\ = { \tt{27 - (x + x)}} \\ = { \tt{27 - 2x}}[/tex]
18) 94-x-67-x
ANS: 94-67-(x-x)
27-(x+x)
27-2x
hope it helps you
