Answer:
[tex]5z^2+3z[/tex]
Step-by-step explanation:
[tex]z\left(5z+3\right)=z\cdot \:5z+z\cdot \:3\\z\cdot \:5z+z\cdot \:3\\z \cdot 3 = 3(z)[/tex]
5z becomes squared
[tex]z\cdot \:5z\\= 5z^2[/tex]
z • z = z²
Remove parentheses
[tex]3(z)\\= 3z\\= 5z^2 + 3z[/tex]
Hope this helps.