30*40*x=350

Solution for 30*40*x=350 equation:

30*40*x=350

We move all terms to the left:

30*40*x-(350)=0

Wy multiply elements

1200x*x-350=0

Wy multiply elements

1200x^2-350=0

a = 1200; b = 0; c = -350;
Δ = b2-4ac
Δ = 02-4·1200·(-350)
Δ = 1680000
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:

$\sqrt{\Delta}=\sqrt{1680000}=\sqrt{40000*42}=\sqrt{40000}*\sqrt{42}=200\sqrt{42}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-200\sqrt{42}}{2*1200}=\frac{0-200\sqrt{42}}{2400}
=-\frac{200\sqrt{42}}{2400}
=-\frac{\sqrt{42}}{12}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+200\sqrt{42}}{2*1200}=\frac{0+200\sqrt{42}}{2400}
=\frac{200\sqrt{42}}{2400}
=\frac{\sqrt{42}}{12}
$