(4a+5)(4a+)=0

Solution for (4a+5)(4a+)=0 equation:

(4a+5)(4a+)=0

We add all the numbers together, and all the variables

(4a+5)(+4a)=0

We multiply parentheses ..

(+16a^2+20a)=0

We get rid of parentheses

16a^2+20a=0

a = 16; b = 20; c = 0;
Δ = b2-4ac
Δ = 202-4·16·0
Δ = 400
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{400}=20$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(20)-20}{2*16}=\frac{-40}{32}
=-1+1/4
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(20)+20}{2*16}=\frac{0}{32}
=0
$