80x-16x^2=70

Solution for 80x-16x^2=70 equation:

80x-16x^2=70

We move all terms to the left:

80x-16x^2-(70)=0

a = -16; b = 80; c = -70;
Δ = b2-4ac
Δ = 802-4·(-16)·(-70)
Δ = 1920
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:

$\sqrt{\Delta}=\sqrt{1920}=\sqrt{64*30}=\sqrt{64}*\sqrt{30}=8\sqrt{30}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(80)-8\sqrt{30}}{2*-16}=\frac{-80-8\sqrt{30}}{-32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(80)+8\sqrt{30}}{2*-16}=\frac{-80+8\sqrt{30}}{-32}
$