13430=243x-x^2

Solution for 13430=243x-x^2 equation:

13430=243x-x^2

We move all terms to the left:

13430-(243x-x^2)=0

We get rid of parentheses

x^2-243x+13430=0

a = 1; b = -243; c = +13430;
Δ = b2-4ac
Δ = -2432-4·1·13430
Δ = 5329
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{5329}=73$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-243)-73}{2*1}=\frac{170}{2}
=85
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-243)+73}{2*1}=\frac{316}{2}
=158
$