I rooted my Android Phone and deleted some unwanted apps with google play store, google play services and google text to speech.
Now how to add these apps again (latest version) as a system app for future factory reset?
Download Google Play store here [ http://forum.xda-developers.com/showthread.php?t=1996995 ]. Install it from file manager by clicking APK file. Convert to System app via TitaniumBackup if you've already bought it as this feature is only available in PRO version. Or use this app [ https://play.google.com/store/apps/details?id=de.j4velin.systemappmover ] which is free. You can also move to /system/app folder manually and then set the right permission [and generate odex file] but using app to convert app to system app is safer option.
Download file for Play store and then download and install the Link2SD from Google play store. Now open Link2SD app and go to App file which you want to convert to system files and long press you will see the option to convert file as system. Press ok and reboot.