-0.002x2+3.5x-1000=0

Solution for -0.002x2+3.5x-1000=0 equation:

-0.002x^2+3.5x-1000=0

a = -0.002; b = 3.5; c = -1000;
Δ = b2-4ac
Δ = 3.52-4·(-0.002)·(-1000)
Δ = 4.25
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{-(3.5)-\sqrt{4.25}}{2*-0.002}=\frac{-3.5-\sqrt{4.25}}{-0.004}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(3.5)+\sqrt{4.25}}{2*-0.002}=\frac{-3.5+\sqrt{4.25}}{-0.004}
$