A Complex Root and Its Expression
Algebra · 27th PMO Qualifying Stage
Let $a$ be a complex number satisfying the equation $2a^2=5a-4$. Then the value of $\dfrac{a^3}{a^6+8}$ is
A$\dfrac{4}{5}$
B$\dfrac{8}{5}$
C$\dfrac{12}{5}$
D$\dfrac{16}{5}$