5z*3z=72

Solution for 5z*3z=72 equation:

5z*3z=72

We move all terms to the left:

5z*3z-(72)=0

Wy multiply elements

15z^2-72=0

a = 15; b = 0; c = -72;
Δ = b2-4ac
Δ = 02-4·15·(-72)
Δ = 4320
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

The end solution:

$\sqrt{\Delta}=\sqrt{4320}=\sqrt{144*30}=\sqrt{144}*\sqrt{30}=12\sqrt{30}$
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(0)-12\sqrt{30}}{2*15}=\frac{0-12\sqrt{30}}{30}
=-\frac{12\sqrt{30}}{30}
=-\frac{2\sqrt{30}}{5}
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(0)+12\sqrt{30}}{2*15}=\frac{0+12\sqrt{30}}{30}
=\frac{12\sqrt{30}}{30}
=\frac{2\sqrt{30}}{5}
$