-16x^2+84x=0

Solution for -16x^2+84x=0 equation:

-16x^2+84x=0

a = -16; b = 84; c = 0;
Δ = b2-4ac
Δ = 842-4·(-16)·0
Δ = 7056
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{7056}=84$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(84)-84}{2*-16}=\frac{-168}{-32}
=5+1/4
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(84)+84}{2*-16}=\frac{0}{-32}
=0
$