(5-2x)(x-5)=0

Solution for (5-2x)(x-5)=0 equation:

(5-2x)(x-5)=0

We add all the numbers together, and all the variables

(-2x+5)(x-5)=0

We multiply parentheses ..

(-2x^2+10x+5x-25)=0

We get rid of parentheses

-2x^2+10x+5x-25=0

We add all the numbers together, and all the variables

-2x^2+15x-25=0

a = -2; b = 15; c = -25;
Δ = b2-4ac
Δ = 152-4·(-2)·(-25)
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(15)-5}{2*-2}=\frac{-20}{-4}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(15)+5}{2*-2}=\frac{-10}{-4}
=2+1/2
$