0,5x^2-2,5x-12=0

Solution for 0,5x^2-2,5x-12=0 equation:

0.5x^2-2.5x-12=0

a = 0.5; b = -2.5; c = -12;
Δ = b2-4ac
Δ = -2.52-4·0.5·(-12)
Δ = 30.25
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{-(-2.5)-\sqrt{30.25}}{2*0.5}=\frac{2.5-\sqrt{30.25}}{1}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2.5)+\sqrt{30.25}}{2*0.5}=\frac{2.5+\sqrt{30.25}}{1}
$