2x+3x(26-x)=58

Solution for 2x+3x(26-x)=58 equation:

2x+3x(26-x)=58

We move all terms to the left:

2x+3x(26-x)-(58)=0

We add all the numbers together, and all the variables

2x+3x(-1x+26)-58=0

We multiply parentheses

-3x^2+2x+78x-58=0

We add all the numbers together, and all the variables

-3x^2+80x-58=0

a = -3; b = 80; c = -58;
Δ = b2-4ac
Δ = 802-4·(-3)·(-58)
Δ = 5704
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:

$\sqrt{\Delta}=\sqrt{5704}=\sqrt{4*1426}=\sqrt{4}*\sqrt{1426}=2\sqrt{1426}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(80)-2\sqrt{1426}}{2*-3}=\frac{-80-2\sqrt{1426}}{-6}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(80)+2\sqrt{1426}}{2*-3}=\frac{-80+2\sqrt{1426}}{-6}
$