.11x+13x(x+200)=50

Solution for .11x+13x(x+200)=50 equation:

.11x+13x(x+200)=50

We move all terms to the left:

.11x+13x(x+200)-(50)=0

We multiply parentheses

13x^2+.11x+2600x-50=0

We add all the numbers together, and all the variables

13x^2+2600.11x-50=0

a = 13; b = 2600.11; c = -50;
Δ = b2-4ac
Δ = 2600.112-4·13·(-50)
Δ = 6763172.0121
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(2600.11)-\sqrt{6763172.0121}}{2*13}=\frac{-2600.11-\sqrt{6763172.0121}}{26}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(2600.11)+\sqrt{6763172.0121}}{2*13}=\frac{-2600.11+\sqrt{6763172.0121}}{26}
$