(x-1.4)(x-1.4)+(-2x+2.8)(-2x+2.8)=0.128164

Solution for (x-1.4)(x-1.4)+(-2x+2.8)(-2x+2.8)=0.128164 equation:

(x-1.4)(x-1.4)+(-2x+2.8)(-2x+2.8)=0.128164

We move all terms to the left:

(x-1.4)(x-1.4)+(-2x+2.8)(-2x+2.8)-(0.128164)=0

We add all the numbers together, and all the variables

(x-1.4)(x-1.4)+(-2x+2.8)(-2x+2.8)-0.128164=0

We multiply parentheses ..

(+x^2-1.4x-1.4x+1.96)+(-2x+2.8)(-2x+2.8)-0.128164=0

We get rid of parentheses

x^2-1.4x-1.4x+(-2x+2.8)(-2x+2.8)+1.96-0.128164=0

We multiply parentheses ..

x^2+(+4x^2-5.6x-5.6x+7.84)-1.4x-1.4x+1.96-0.128164=0

We add all the numbers together, and all the variables

x^2+(+4x^2-5.6x-5.6x+7.84)-2.8x+1.831836=0

We get rid of parentheses

x^2+4x^2-5.6x-5.6x-2.8x+7.84+1.831836=0

We add all the numbers together, and all the variables

5x^2-14x+9.671836=0

a = 5; b = -14; c = +9.671836;
Δ = b2-4ac
Δ = -142-4·5·9.671836
Δ = 2.56328
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{-(-14)-\sqrt{2.56328}}{2*5}=\frac{14-\sqrt{2.56328}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-14)+\sqrt{2.56328}}{2*5}=\frac{14+\sqrt{2.56328}}{10}
$