2.5=x^2-2.5x

Solution for 2.5=x^2-2.5x equation:

2.5=x^2-2.5x

We move all terms to the left:

2.5-(x^2-2.5x)=0

We get rid of parentheses

-x^2+2.5x+2.5=0

We add all the numbers together, and all the variables

-1x^2+2.5x+2.5=0

a = -1; b = 2.5; c = +2.5;
Δ = b2-4ac
Δ = 2.52-4·(-1)·2.5
Δ = 16.25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2.5)-\sqrt{16.25}}{2*-1}=\frac{-2.5-\sqrt{16.25}}{-2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2.5)+\sqrt{16.25}}{2*-1}=\frac{-2.5+\sqrt{16.25}}{-2}
$