40-8x(x=2)

Solution for 40-8x(x=2) equation:

40-8x(x=2)

We move all terms to the left:

40-8x(x-(2))=0

We multiply parentheses

-8x^2+16x+40=0

a = -8; b = 16; c = +40;
Δ = b2-4ac
Δ = 162-4·(-8)·40
Δ = 1536
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:

$\sqrt{\Delta}=\sqrt{1536}=\sqrt{256*6}=\sqrt{256}*\sqrt{6}=16\sqrt{6}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(16)-16\sqrt{6}}{2*-8}=\frac{-16-16\sqrt{6}}{-16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(16)+16\sqrt{6}}{2*-8}=\frac{-16+16\sqrt{6}}{-16}
$