Answer:
7z²+3z
Step-by-step explanation:
z(7z+3)
[tex]z(7z+3)\\[/tex]
Expand
[tex]\mathrm{Apply\:the\:distributive\:law}:\quad \:a\left(b+c\right)=ab+ac\\\\a=z,\:b=7z,\:c=3\\\\=z\times\:7z+z\times\:3\\\\=7zz+3z\\\\7zz=7z^2\\\\=7z^2+3z[/tex]
