Answer
$z=3.75$
Work Step by Step
Start with the given equation: $5(2+4z)=85$
We use the distributive property to expand the left side of the equation: $10+20z=85$
We subtract $10$ from both sides of the equation: $20z=85-10$
We combine like terms: $20z=75$
We divide both sides of the equation by $20$: $z=\frac{75}{20}=3.75$