### Extract solutions from solve

I am new to sage. So, sorry if my question is trivial.

How can I get the values of a solve operation. Say I have

```
x = var('x');
f = x^2 - 5*x + 6;
z = solve(f = 0, x);
show(z);
```

gives me something like

```
[x == 2, x == 3]
```

How can I take the value 2 or 3 from that?

Also, when I was trying to solve another equation (quiet a long one), I get the solution as

```
[0 = something something.....]
```

What does that zero mean?