The function fff is defined by f(x)=5(4)−x6f(x)=5(4)^{-\dfrac{x}{6}}f(x)=5(4)−6x. What is the value of f(12)f(12)f(12)?A−80-80−80B−40-40−40C1400\dfrac{1}{400}4001D516\dfrac{5}{16}165Check answerShow answerExplanationAnswer: D. 516\dfrac{5}{16}165 Explanation: f(12)=5(4)−126=5(4)−2=5⋅116=516.f(12)=5(4)^{-\dfrac{12}{6}}=5(4)^{-2}=5\cdot\dfrac{1}{16}=\dfrac{5}{16}.f(12)=5(4)−612=5(4)−2=5⋅161=165.
