7z2=5z

Solution for 7z2=5z equation:

7z^2=5z

We move all terms to the left:

7z^2-(5z)=0

a = 7; b = -5; c = 0;
Δ = b2-4ac
Δ = -52-4·7·0
Δ = 25
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{25}=5$
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(-5)-5}{2*7}=\frac{0}{14}
=0
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(-5)+5}{2*7}=\frac{10}{14}
=5/7
$