x2-9x-4.75=0

Solution for x2-9x-4.75=0 equation:

x2-9x-4.75=0

We add all the numbers together, and all the variables

x^2-9x-4.75=0

a = 1; b = -9; c = -4.75;
Δ = b2-4ac
Δ = -92-4·1·(-4.75)
Δ = 100
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{100}=10$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-9)-10}{2*1}=\frac{-1}{2}
=-1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-9)+10}{2*1}=\frac{19}{2}
=9+1/2
$