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

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

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

We multiply parentheses ..

(+6a^2-36a+5a-30)=0

We get rid of parentheses

6a^2-36a+5a-30=0

We add all the numbers together, and all the variables

6a^2-31a-30=0

a = 6; b = -31; c = -30;
Δ = b2-4ac
Δ = -312-4·6·(-30)
Δ = 1681
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1681}=41$
$a_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-31)-41}{2*6}=\frac{-10}{12}
=-5/6
$
$a_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-31)+41}{2*6}=\frac{72}{12}
=6
$