how to find equivalent resistance of this circuit?

Answer:
R_eq=35.425 ohm
Explanation:
If we want to find the equivalent resistance across the output terminals, we know that all the resistors will be considered and battery's internal resistance will be added instead of battery.
[tex]R_{10||7}={10*7}/{107}=70/17[/tex]
then
R_e1= [tex]R_{10||7}+R20=410/17[/tex]=24.12
and then
R_e2={24.12}//{24.12+7}=5.425
and finally
R_e=5.24+30=35.425