(1.4-x)(.8-x)=0

Solution for (1.4-x)(.8-x)=0 equation:

(1.4-x)(.8-x)=0

We add all the numbers together, and all the variables

(-1x+1.4)(-1x+0.8)=0

We multiply parentheses ..

(+x^2-0.8x-1.4x+1.12)=0

We get rid of parentheses

x^2-0.8x-1.4x+1.12=0

We add all the numbers together, and all the variables

x^2-2.2x+1.12=0

a = 1; b = -2.2; c = +1.12;
Δ = b2-4ac
Δ = -2.22-4·1·1.12
Δ = 0.36
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{-(-2.2)-\sqrt{0.36}}{2*1}=\frac{2.2-\sqrt{0.36}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2.2)+\sqrt{0.36}}{2*1}=\frac{2.2+\sqrt{0.36}}{2}
$