139.8=z^2

Solution for 139.8=z^2 equation:

139.8=z^2

We move all terms to the left:

139.8-(z^2)=0

We add all the numbers together, and all the variables

-1z^2+139.8=0

a = -1; b = 0; c = +139.8;
Δ = b2-4ac
Δ = 02-4·(-1)·139.8
Δ = 559.2
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-\sqrt{559.2}}{2*-1}=\frac{0-\sqrt{559.2}}{-2}
=-\frac{\sqrt{}}{-2}
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+\sqrt{559.2}}{2*-1}=\frac{0+\sqrt{559.2}}{-2}
=\frac{\sqrt{}}{-2}
$