7z^2+73z+30=0

Solution for 7z^2+73z+30=0 equation:

7z^2+73z+30=0

a = 7; b = 73; c = +30;
Δ = b2-4ac
Δ = 732-4·7·30
Δ = 4489
The delta value is higher than zero, so the equation has two solutions
We use following formulas to calculate our solutions:
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}$

$\sqrt{\Delta}=\sqrt{4489}=67$
$z_{1}=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-(73)-67}{2*7}=\frac{-140}{14}
=-10
$
$z_{2}=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-(73)+67}{2*7}=\frac{-6}{14}
=-3/7
$