(2x-20)(x=15)

Solution for (2x-20)(x=15) equation:

(2x-20)(x=15)

We move all terms to the left:

(2x-20)(x-(15))=0

We multiply parentheses ..

(+2x^2-30x-20x+300)=0

We get rid of parentheses

2x^2-30x-20x+300=0

We add all the numbers together, and all the variables

2x^2-50x+300=0

a = 2; b = -50; c = +300;
Δ = b2-4ac
Δ = -502-4·2·300
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-50)-10}{2*2}=\frac{40}{4}
=10
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-50)+10}{2*2}=\frac{60}{4}
=15
$