(3x-30)(2x-10)=0

Solution for (3x-30)(2x-10)=0 equation:

(3x-30)(2x-10)=0

We multiply parentheses ..

(+6x^2-30x-60x+300)=0

We get rid of parentheses

6x^2-30x-60x+300=0

We add all the numbers together, and all the variables

6x^2-90x+300=0

a = 6; b = -90; c = +300;
Δ = b2-4ac
Δ = -902-4·6·300
Δ = 900
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{900}=30$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-90)-30}{2*6}=\frac{60}{12}
=5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-90)+30}{2*6}=\frac{120}{12}
=10
$