-16x^2+72x=56

Solution for -16x^2+72x=56 equation:

-16x^2+72x=56

We move all terms to the left:

-16x^2+72x-(56)=0

a = -16; b = 72; c = -56;
Δ = b2-4ac
Δ = 722-4·(-16)·(-56)
Δ = 1600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{1600}=40$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(72)-40}{2*-16}=\frac{-112}{-32}
=3+1/2
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(72)+40}{2*-16}=\frac{-32}{-32}
=1
$