Question

(z+1)³ - 7z = 5 + z² × (z+3)​

Answer 1

$\displaystyle\bf\\(z+1)^{3} -7z=5+z^{2} \cdot(z+3)\\\\z^{3} +3z^{2} +3z+1-7z=z^{3}+3z^{2} \\\\z^{3} +3z^{2} +1-4z-z^{3}-3z^{2} =0\\\\1-4z=0\\\\4z=1\\\\\boxed{z=0,25}$