(9x+18)(8x-6)=0

Solution for (9x+18)(8x-6)=0 equation:

(9x+18)(8x-6)=0

We multiply parentheses ..

(+72x^2-54x+144x-108)=0

We get rid of parentheses

72x^2-54x+144x-108=0

We add all the numbers together, and all the variables

72x^2+90x-108=0

a = 72; b = 90; c = -108;
Δ = b2-4ac
Δ = 902-4·72·(-108)
Δ = 39204
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{39204}=198$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(90)-198}{2*72}=\frac{-288}{144}
=-2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(90)+198}{2*72}=\frac{108}{144}
=3/4
$