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

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

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

We multiply parentheses ..

(+4x^2-6x-60x+90)=0

We get rid of parentheses

4x^2-6x-60x+90=0

We add all the numbers together, and all the variables

4x^2-66x+90=0

a = 4; b = -66; c = +90;
Δ = b2-4ac
Δ = -662-4·4·90
Δ = 2916
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{2916}=54$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-66)-54}{2*4}=\frac{12}{8}
=1+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-66)+54}{2*4}=\frac{120}{8}
=15
$