7x2-160x-28=0

Solution for 7x2-160x-28=0 equation:

7x^2-160x-28=0

a = 7; b = -160; c = -28;
Δ = b2-4ac
Δ = -1602-4·7·(-28)
Δ = 26384
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{26384}=\sqrt{16*1649}=\sqrt{16}*\sqrt{1649}=4\sqrt{1649}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-160)-4\sqrt{1649}}{2*7}=\frac{160-4\sqrt{1649}}{14}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-160)+4\sqrt{1649}}{2*7}=\frac{160+4\sqrt{1649}}{14}
$