(2x+10)*(x)=80

Solution for (2x+10)*(x)=80 equation:

(2x+10)(x)=80

We move all terms to the left:

(2x+10)(x)-(80)=0

We multiply parentheses

2x^2+10x-80=0

a = 2; b = 10; c = -80;
Δ = b2-4ac
Δ = 102-4·2·(-80)
Δ = 740
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:

$\sqrt{\Delta}=\sqrt{740}=\sqrt{4*185}=\sqrt{4}*\sqrt{185}=2\sqrt{185}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(10)-2\sqrt{185}}{2*2}=\frac{-10-2\sqrt{185}}{4}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(10)+2\sqrt{185}}{2*2}=\frac{-10+2\sqrt{185}}{4}
$