5*(29.6-x)x=26

Solution for 5*(29.6-x)x=26 equation:

5*(29.6-x)x=26

We move all terms to the left:

5*(29.6-x)x-(26)=0

We add all the numbers together, and all the variables

5*(-1x+29.6)x-26=0

We multiply parentheses

-5x^2+148x-26=0

a = -5; b = 148; c = -26;
Δ = b2-4ac
Δ = 1482-4·(-5)·(-26)
Δ = 21384
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:

$\sqrt{\Delta}=\sqrt{21384}=\sqrt{324*66}=\sqrt{324}*\sqrt{66}=18\sqrt{66}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(148)-18\sqrt{66}}{2*-5}=\frac{-148-18\sqrt{66}}{-10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(148)+18\sqrt{66}}{2*-5}=\frac{-148+18\sqrt{66}}{-10}
$