-5x^2+10x-1.8=0

Solution for -5x^2+10x-1.8=0 equation:

-5x^2+10x-1.8=0

a = -5; b = 10; c = -1.8;
Δ = b2-4ac
Δ = 102-4·(-5)·(-1.8)
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-8}{2*-5}=\frac{-18}{-10}
=1+4/5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+8}{2*-5}=\frac{-2}{-10}
=1/5
$