(5a+4)(a-6)=0

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

(5a+4)(a-6)=0

We multiply parentheses ..

(+5a^2-30a+4a-24)=0

We get rid of parentheses

5a^2-30a+4a-24=0

We add all the numbers together, and all the variables

5a^2-26a-24=0

a = 5; b = -26; c = -24;
Δ = b2-4ac
Δ = -262-4·5·(-24)
Δ = 1156
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1156}=34$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-26)-34}{2*5}=\frac{-8}{10}
=-4/5
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-26)+34}{2*5}=\frac{60}{10}
=6
$