.005x^2-0.3x-4=25

Solution for .005x^2-0.3x-4=25 equation:

.005x^2-0.3x-4=25

We move all terms to the left:

.005x^2-0.3x-4-(25)=0

We add all the numbers together, and all the variables

.005x^2-0.3x-29=0

a = .005; b = -0.3; c = -29;
Δ = b2-4ac
Δ = -0.32-4·.005·(-29)
Δ = 0.67
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{-(-0.3)-\sqrt{0.67}}{2*.005}=\frac{0.3-\sqrt{0.67}}{0.01}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-0.3)+\sqrt{0.67}}{2*.005}=\frac{0.3+\sqrt{0.67}}{0.01}
$