x2=8.1x-4.5

Solution for x2=8.1x-4.5 equation:

x2=8.1x-4.5

We move all terms to the left:

x2-(8.1x-4.5)=0

We add all the numbers together, and all the variables

x^2-(8.1x-4.5)=0

We get rid of parentheses

x^2-8.1x+4.5=0

a = 1; b = -8.1; c = +4.5;
Δ = b2-4ac
Δ = -8.12-4·1·4.5
Δ = 47.61
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{-(-8.1)-\sqrt{47.61}}{2*1}=\frac{8.1-\sqrt{47.61}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-8.1)+\sqrt{47.61}}{2*1}=\frac{8.1+\sqrt{47.61}}{2}
$