-4x^2+16x-4=8

Solution for -4x^2+16x-4=8 equation:

-4x^2+16x-4=8

We move all terms to the left:

-4x^2+16x-4-(8)=0

We add all the numbers together, and all the variables

-4x^2+16x-12=0

a = -4; b = 16; c = -12;
Δ = b2-4ac
Δ = 162-4·(-4)·(-12)
Δ = 64
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{64}=8$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-8}{2*-4}=\frac{-24}{-8}
=+3
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+8}{2*-4}=\frac{-8}{-8}
=1
$