\"\"

\

The expression is \"\"                  

\

\"\"              (Replace a with 5 and c with 4 in original expression)\"\"

\

Simplify the expression using order of operations (PEMDAS).

\

Since there are no grouping symbols and powers, product and quotients,

\

First operation is addition.

\

\"\"                    (Add: \"\")

\

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

\

The value of the expression is 21.