20-8x(x=2)

Solution for 20-8x(x=2) equation:

20-8x(x=2)

We move all terms to the left:

20-8x(x-(2))=0

We multiply parentheses

-8x^2+16x+20=0

a = -8; b = 16; c = +20;
Δ = b2-4ac
Δ = 162-4·(-8)·20
Δ = 896
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{896}=\sqrt{64*14}=\sqrt{64}*\sqrt{14}=8\sqrt{14}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-8\sqrt{14}}{2*-8}=\frac{-16-8\sqrt{14}}{-16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+8\sqrt{14}}{2*-8}=\frac{-16+8\sqrt{14}}{-16}
$