5=-0.005x^2+1.2x+10

Solution for 5=-0.005x^2+1.2x+10 equation:

5=-0.005x^2+1.2x+10

We move all terms to the left:

5-(-0.005x^2+1.2x+10)=0

We get rid of parentheses

0.005x^2-1.2x-10+5=0

We add all the numbers together, and all the variables

0.005x^2-1.2x-5=0

a = 0.005; b = -1.2; c = -5;
Δ = b2-4ac
Δ = -1.22-4·0.005·(-5)
Δ = 1.54
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{-(-1.2)-\sqrt{1.54}}{2*0.005}=\frac{1.2-\sqrt{1.54}}{0.01}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.2)+\sqrt{1.54}}{2*0.005}=\frac{1.2+\sqrt{1.54}}{0.01}
$