26=54x-5x^2

Solution for 26=54x-5x^2 equation:

26=54x-5x^2

We move all terms to the left:

26-(54x-5x^2)=0

We get rid of parentheses

5x^2-54x+26=0

a = 5; b = -54; c = +26;
Δ = b2-4ac
Δ = -542-4·5·26
Δ = 2396
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:

$\sqrt{\Delta}=\sqrt{2396}=\sqrt{4*599}=\sqrt{4}*\sqrt{599}=2\sqrt{599}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-54)-2\sqrt{599}}{2*5}=\frac{54-2\sqrt{599}}{10}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-54)+2\sqrt{599}}{2*5}=\frac{54+2\sqrt{599}}{10}
$