How to delete from app store?

I downloaded Clean My Mac, but taking advice from here I'm not going to use it. I want to delete it.

I can't see any way to delete apps from my Purchased list at the app store, and the app won't delete from my computer. Won't go into the trash, and no black cross comes up in the corner.

There must be a way?

 

this is weird ... the app icon for Clean My Mac is still on my computer, but when i go to the Purchased list now it isn't there. The app i did delete, the Clean My Mac for external drives has gone from my desktop but still shows up in the App store list.

How can something not in the purchased list be on my computer?

There seems to be no way to delete apps from the Purchased list?

 

When the app starts to shake, no black cross appears to delete it, and when I drag it to trash it just won't go in.

Haven't had a chance to try the other remedies yet, will post when I have. But it is strange ... I never activated the app, it doesn't appear in my Purchased list but it is on my computer and I did get it from the App Store. When I open it, it is asking me to activate it. The companion app for cleaning external drives deleted from the computer be being dragged to trash.

Another weird thing ...when I did secure empty trash, it said it was deleting 1,700 things! I stopped it to look at what it was deleting, there was only VLC dmg in there, from recent update of that app. But when I resumed emptying trash it still gave this number and took as long as you'd expect to delete a lot rather than one thing. Hmmmm.

I've been busy with work, haven't had time to investigate further yet. I haven't got 1700 things on the computer, so I don't know what it was deleting!