0=-5x^2+10x+1.6

Solution for 0=-5x^2+10x+1.6 equation:

0=-5x^2+10x+1.6

We move all terms to the left:

0-(-5x^2+10x+1.6)=0

We add all the numbers together, and all the variables

-(-5x^2+10x+1.6)=0

We get rid of parentheses

5x^2-10x-1.6=0

a = 5; b = -10; c = -1.6;
Δ = b2-4ac
Δ = -102-4·5·(-1.6)
Δ = 132
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{132}=\sqrt{4*33}=\sqrt{4}*\sqrt{33}=2\sqrt{33}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-10)-2\sqrt{33}}{2*5}=\frac{10-2\sqrt{33}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-10)+2\sqrt{33}}{2*5}=\frac{10+2\sqrt{33}}{10}
$