Android Question About Activity.Finish

hi, its possible to re-open the finish activity without lack of memory?

i have 10 activitys, sometimes i want to open activity2 , sometimes 3 etc but if i use activity.finish
when i go call this activity again i have error memory, what i make ? i cant close activity?

if i use FirstTime to loadlayout i have error when start activity again, layout dont start
activity.finish dont close total the activity, this ignore FirstTime

and if i dont use FirstTime when i open the activity 2 or 3 times i have problem with memory *-*
what i make *-*