# Equations solving

Hi everybody, i've got this two equations:

```
eqq0: V_f*cos(delta(t))=v(t)
eqq1: V_f*sin(delta(t))=l*diff(psi(t))
```

I need to isolate V_f from the first equation, obtaining V_f=v(t)/cos(delta(t)) and substitute it in the second equation. Then i have to isolate diff(psi(t))=[v(t)*tan(delta(t))]/l.

I did :

```
a=solve (eqq0,V_f)
V_ff=a.right()
```

but it says *"AttributeError: 'Sequence_generic' object has no attribute 'right'"*

How can i solve this two equations?

Thank you.