.7x^2-2x-10.4=0

Solution for .7x^2-2x-10.4=0 equation:

.7x^2-2x-10.4=0

a = .7; b = -2; c = -10.4;
Δ = b2-4ac
Δ = -22-4·.7·(-10.4)
Δ = 33.12
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)-\sqrt{33.12}}{2*.7}=\frac{2-\sqrt{33.12}}{1.4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-2)+\sqrt{33.12}}{2*.7}=\frac{2+\sqrt{33.12}}{1.4}
$