X^2+6.5x-12=0

Solution for X^2+6.5x-12=0 equation:

X^2+6.5X-12=0

a = 1; b = 6.5; c = -12;
Δ = b2-4ac
Δ = 6.52-4·1·(-12)
Δ = 90.25
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{-(6.5)-\sqrt{90.25}}{2*1}=\frac{-6.5-\sqrt{90.25}}{2}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(6.5)+\sqrt{90.25}}{2*1}=\frac{-6.5+\sqrt{90.25}}{2}
$