Solving a 'Stanford' University entrance exam | t=?

To solve the equation (t^4)/(4t) = 80/5, simplify to t^3/4 = 16, then t^3 = 64, giving t = 4 as the real solution. Using the difference of cubes formula a^3 - b^3 = (a-b)(a^2 + ab + b^2), the equation factors to (t-4)(t^2 + 4t + 16) = 0. The quadratic factor t^2 + 4t + 16 = 0 yields complex solutions t = -2 ± 2√3i using the quadratic formula. All three solutions (t = 4, t = -2 + 2√3i, t = -2 - 2√3i) satisfy the original equation.