What is the sum of the the roots of the equation $4x^3 + 5x^2 - 8x = 0$? Express your answer as a decimal to the nearest hundredth.
To find the sum of the roots of a cubic equation, I need to use a formula that relates the coefficients of the equation to the roots. I recall that for a cubic equation of the form $ax^3 + bx^2 + cx + d = 0$, the sum of the roots is $-\frac{b}{a}$. In this case, $a = 4$, $b = 5$, $c = -8$, and $d = 0$. So the sum of the roots is $-\frac{5}{4}$. I get -1.25 as the decimal. Rounding to the nearest hundredth, I get -1.25 as the final answer.

