-16x^2+41.6x=4

Solution for -16x^2+41.6x=4 equation:

-16x^2+41.6x=4

We move all terms to the left:

-16x^2+41.6x-(4)=0

a = -16; b = 41.6; c = -4;
Δ = b2-4ac
Δ = 41.62-4·(-16)·(-4)
Δ = 1474.56
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{-(41.6)-\sqrt{1474.56}}{2*-16}=\frac{-41.6-\sqrt{1474.56}}{-32}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(41.6)+\sqrt{1474.56}}{2*-16}=\frac{-41.6+\sqrt{1474.56}}{-32}
$