X*y=1200

Solution for X*y=1200 equation:

X*X=1200

We move all terms to the left:

X*X-(1200)=0

Wy multiply elements

X^2-1200=0

a = 1; b = 0; c = -1200;
Δ = b2-4ac
Δ = 02-4·1·(-1200)
Δ = 4800
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:

$\sqrt{\Delta}=\sqrt{4800}=\sqrt{1600*3}=\sqrt{1600}*\sqrt{3}=40\sqrt{3}$
$X_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-40\sqrt{3}}{2*1}=\frac{0-40\sqrt{3}}{2}
=-\frac{40\sqrt{3}}{2}
=-20\sqrt{3}
$
$X_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+40\sqrt{3}}{2*1}=\frac{0+40\sqrt{3}}{2}
=\frac{40\sqrt{3}}{2}
=20\sqrt{3}
$