350=14x*x

Solution for 350=14x*x equation:

350=14x*x

We move all terms to the left:

350-(14x*x)=0

We add all the numbers together, and all the variables

-(+14x*x)+350=0

We get rid of parentheses

-14x*x+350=0

Wy multiply elements

-14x^2+350=0

a = -14; b = 0; c = +350;
Δ = b2-4ac
Δ = 02-4·(-14)·350
Δ = 19600
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{19600}=140$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-140}{2*-14}=\frac{-140}{-28}
=+5
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+140}{2*-14}=\frac{140}{-28}
=-5
$