16=0.1x^2-0.5x

Solution for 16=0.1x^2-0.5x equation:

16=0.1x^2-0.5x

We move all terms to the left:

16-(0.1x^2-0.5x)=0

We get rid of parentheses

-0.1x^2+0.5x+16=0

a = -0.1; b = 0.5; c = +16;
Δ = b2-4ac
Δ = 0.52-4·(-0.1)·16
Δ = 6.65
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{-(0.5)-\sqrt{6.65}}{2*-0.1}=\frac{-0.5-\sqrt{6.65}}{-0.2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.5)+\sqrt{6.65}}{2*-0.1}=\frac{-0.5+\sqrt{6.65}}{-0.2}
$