x2+0.25x-9=0

Solution for x2+0.25x-9=0 equation:

x2+0.25x-9=0

We add all the numbers together, and all the variables

x^2+0.25x-9=0

a = 1; b = 0.25; c = -9;
Δ = b2-4ac
Δ = 0.252-4·1·(-9)
Δ = 36.0625
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{-(0.25)-\sqrt{36.0625}}{2*1}=\frac{-0.25-\sqrt{36.0625}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0.25)+\sqrt{36.0625}}{2*1}=\frac{-0.25+\sqrt{36.0625}}{2}
$