\"\"

\

The expression is \"\".

\

\

\"\"             (Substitute x = 3.6, y = 6.6 and z =  –11)

\

To subtract 6.6 means add – 6.6.

\

\"\"

\

 

\

\"\"                       (Add: \"\")\"\"

\

To subtract – 11 means add 11.

\

\"\"

\

\"\"                                             (Add: \"\")

\

\"\"                                               (Subtract: \"\") \ \ \"\"

\

The value of the expression is – 4.2.