(5u)(3+u)=0

Solution for (5u)(3+u)=0 equation:

(5u)(3+u)=0

We add all the numbers together, and all the variables

5u(u+3)=0

We multiply parentheses

5u^2+15u=0

a = 5; b = 15; c = 0;
Δ = b2-4ac
Δ = 152-4·5·0
Δ = 225
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{225}=15$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-15}{2*5}=\frac{-30}{10}
=-3
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+15}{2*5}=\frac{0}{10}
=0
$