x2*10=1200

Solution for x2*10=1200 equation:

x2*10=1200

We move all terms to the left:

x2*10-(1200)=0

Wy multiply elements

10x^2-1200=0

a = 10; b = 0; c = -1200;
Δ = b2-4ac
Δ = 02-4·10·(-1200)
Δ = 48000
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:

$\sqrt{\Delta}=\sqrt{48000}=\sqrt{1600*30}=\sqrt{1600}*\sqrt{30}=40\sqrt{30}$
$x_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-40\sqrt{30}}{2*10}=\frac{0-40\sqrt{30}}{20}
=-\frac{40\sqrt{30}}{20}
=-2\sqrt{30}
$
$x_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+40\sqrt{30}}{2*10}=\frac{0+40\sqrt{30}}{20}
=\frac{40\sqrt{30}}{20}
=2\sqrt{30}
$