126=-2x^2+32x

Solution for 126=-2x^2+32x equation:

126=-2x^2+32x

We move all terms to the left:

126-(-2x^2+32x)=0

We get rid of parentheses

2x^2-32x+126=0

a = 2; b = -32; c = +126;
Δ = b2-4ac
Δ = -322-4·2·126
Δ = 16
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{16}=4$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-32)-4}{2*2}=\frac{28}{4}
=7
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-32)+4}{2*2}=\frac{36}{4}
=9
$