(3x+6)*(9x-13)=0

Solution for (3x+6)*(9x-13)=0 equation:

(3x+6)(9x-13)=0

We multiply parentheses ..

(+27x^2-39x+54x-78)=0

We get rid of parentheses

27x^2-39x+54x-78=0

We add all the numbers together, and all the variables

27x^2+15x-78=0

a = 27; b = 15; c = -78;
Δ = b2-4ac
Δ = 152-4·27·(-78)
Δ = 8649
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{8649}=93$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-93}{2*27}=\frac{-108}{54}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+93}{2*27}=\frac{78}{54}
=1+4/9
$