0=-0.01x^2-10x+1989

Solution for 0=-0.01x^2-10x+1989 equation:

0=-0.01x^2-10x+1989

We move all terms to the left:

0-(-0.01x^2-10x+1989)=0

We add all the numbers together, and all the variables

-(-0.01x^2-10x+1989)=0

We get rid of parentheses

0.01x^2+10x-1989=0

a = 0.01; b = 10; c = -1989;
Δ = b2-4ac
Δ = 102-4·0.01·(-1989)
Δ = 179.56
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{-(10)-\sqrt{179.56}}{2*0.01}=\frac{-10-\sqrt{179.56}}{0.02}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+\sqrt{179.56}}{2*0.01}=\frac{-10+\sqrt{179.56}}{0.02}
$