(3x-18)(5x-10)=0

Solution for (3x-18)(5x-10)=0 equation:

(3x-18)(5x-10)=0

We multiply parentheses ..

(+15x^2-30x-90x+180)=0

We get rid of parentheses

15x^2-30x-90x+180=0

We add all the numbers together, and all the variables

15x^2-120x+180=0

a = 15; b = -120; c = +180;
Δ = b2-4ac
Δ = -1202-4·15·180
Δ = 3600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{3600}=60$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-120)-60}{2*15}=\frac{60}{30}
=2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-120)+60}{2*15}=\frac{180}{30}
=6
$