-3.5x^2+35x-80=0

Solution for -3.5x^2+35x-80=0 equation:

-3.5x^2+35x-80=0

a = -3.5; b = 35; c = -80;
Δ = b2-4ac
Δ = 352-4·(-3.5)·(-80)
Δ = 105
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{-(35)-\sqrt{105}}{2*-3.5}=\frac{-35-\sqrt{105}}{-7}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(35)+\sqrt{105}}{2*-3.5}=\frac{-35+\sqrt{105}}{-7}
$