x^2-7.5x+9=0

Solution for x^2-7.5x+9=0 equation:

x^2-7.5x+9=0

a = 1; b = -7.5; c = +9;
Δ = b2-4ac
Δ = -7.52-4·1·9
Δ = 20.25
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{-(-7.5)-\sqrt{20.25}}{2*1}=\frac{7.5-\sqrt{20.25}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-7.5)+\sqrt{20.25}}{2*1}=\frac{7.5+\sqrt{20.25}}{2}
$