x^2-1.4x-0.3=0

Solution for x^2-1.4x-0.3=0 equation:

x^2-1.4x-0.3=0

a = 1; b = -1.4; c = -0.3;
Δ = b2-4ac
Δ = -1.42-4·1·(-0.3)
Δ = 3.16
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{-(-1.4)-\sqrt{3.16}}{2*1}=\frac{1.4-\sqrt{3.16}}{2}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-1.4)+\sqrt{3.16}}{2*1}=\frac{1.4+\sqrt{3.16}}{2}
$