Unable to delete downloaded applications on iPad 2(WiFi)?

As I updated my iPad 2 to iOS 8, I am now unable to delete the downloaded apps. When I long press any app like Subway Surf or TOI(Times of India) or anything else, it doesn't show up the cross(x) mark to remove the app, instead the app icon just shivers at its place just like any factory installed app like Safari, Mail etc with no cross(x) mark on it. Some apps are taking a lot of storage on my iPad and it is running pretty slow. I want to delete them. Please help.
