\"\"

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The expression is \"\"                  

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

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\"\"

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Simplify the expression using order of operations (PEMDAS).

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

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First operation is addition.

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\"\"                    (Add: \"\")

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

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\"\"

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The value of the expression is 21.