(a+3)(3a+8)=0

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

(a+3)(3a+8)=0

We multiply parentheses ..

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

We get rid of parentheses

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

We add all the numbers together, and all the variables

3a^2+17a+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:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

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