4u(5u+6)=0

Solution for 4u(5u+6)=0 equation:

4u(5u+6)=0

We multiply parentheses

20u^2+24u=0

a = 20; b = 24; c = 0;
Δ = b2-4ac
Δ = 242-4·20·0
Δ = 576
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{576}=24$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(24)-24}{2*20}=\frac{-48}{40}
=-1+1/5
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(24)+24}{2*20}=\frac{0}{40}
=0
$