(3u+8)(3+u)=0

Solution for (3u+8)(3+u)=0 equation:

(3u+8)(3+u)=0

We add all the numbers together, and all the variables

(3u+8)(u+3)=0

We multiply parentheses ..

(+3u^2+9u+8u+24)=0

We get rid of parentheses

3u^2+9u+8u+24=0

We add all the numbers together, and all the variables

3u^2+17u+24=0

a = 3; b = 17; c = +24;
Δ = b2-4ac
Δ = 172-4·3·24
Δ = 1
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1}=1$
$u_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(17)-1}{2*3}=\frac{-18}{6}
=-3
$
$u_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(17)+1}{2*3}=\frac{-16}{6}
=-2+2/3
$