-(2x+5)4x=10

Solution for -(2x+5)4x=10 equation:

-(2x+5)4x=10

We move all terms to the left:

-(2x+5)4x-(10)=0

We multiply parentheses

-8x^2-20x-10=0

a = -8; b = -20; c = -10;
Δ = b2-4ac
Δ = -202-4·(-8)·(-10)
Δ = 80
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:

$\sqrt{\Delta}=\sqrt{80}=\sqrt{16*5}=\sqrt{16}*\sqrt{5}=4\sqrt{5}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-20)-4\sqrt{5}}{2*-8}=\frac{20-4\sqrt{5}}{-16}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-20)+4\sqrt{5}}{2*-8}=\frac{20+4\sqrt{5}}{-16}
$