-0.1x2+-4.5x+-17.5=0

Solution for -0.1x2+-4.5x+-17.5=0 equation:

-0.1x^2+-4.5x+-17.5=0

We add all the numbers together, and all the variables

-0.1x^2-4.5x=0

a = -0.1; b = -4.5; c = 0;
Δ = b2-4ac
Δ = -4.52-4·(-0.1)·0
Δ = 20.25
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{-(-4.5)-\sqrt{20.25}}{2*-0.1}=\frac{4.5-\sqrt{20.25}}{-0.2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-4.5)+\sqrt{20.25}}{2*-0.1}=\frac{4.5+\sqrt{20.25}}{-0.2}
$