13=-11x^2+350x

Solution for 13=-11x^2+350x equation:

13=-11x^2+350x

We move all terms to the left:

13-(-11x^2+350x)=0

We get rid of parentheses

11x^2-350x+13=0

a = 11; b = -350; c = +13;
Δ = b2-4ac
Δ = -3502-4·11·13
Δ = 121928
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:

$\sqrt{\Delta}=\sqrt{121928}=\sqrt{4*30482}=\sqrt{4}*\sqrt{30482}=2\sqrt{30482}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-350)-2\sqrt{30482}}{2*11}=\frac{350-2\sqrt{30482}}{22}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-350)+2\sqrt{30482}}{2*11}=\frac{350+2\sqrt{30482}}{22}
$