$f(x)=(2 x+1)(x+4)$
Final Answer: \(f(x) = \boxed{2x^2 + 9x + 4}\)
Step 1 :Given the function \(f(x)=(2 x+1)(x+4)\).
Step 2 :This is a multiplication of two binomials. To solve this, we can use the distributive property to multiply each term in the first binomial with each term in the second binomial.
Step 3 :Applying the distributive property, we get \(f(x) = 2x^2 + 9x + 4\).
Step 4 :Final Answer: \(f(x) = \boxed{2x^2 + 9x + 4}\)