Q: Apple wireless keyboard won't pair with macbook air, tried everything!

hi all!

I've been searching forums for 2 days and have tried everything suggested.

Running 10.10.5 on my 2011 Macbook Air. Wireless keyboard worked fine last time I tried to connect them (which was right before I "upgraded" to Yosemite.)

Wireless mouse connects fine. It sees my iPhone and my husbands Macbook pro, bluetooth speaker in the room. But doesn't see keyboard which has new batteries, green light comes on for about 2 seconds then goes off (indicating its already paired).

If I try over and over to search devices sometimes it will see it, then when I click "pair" it just spins forever then says "Cannot connect to device".

Ive shut down computer several times. Disconnected every device and then re-paired one at a time. I've taken batteries out and put them back in. Held the power button while searching.

A lot of the tutorials say to click the - or + in bluetooth preferences (devices) but in Yosemite there is not + or - option at all. Things just are either there or they are not.

I have a new lift on my monitor and it hurts to have my arms up high to type which is why I'm trying to use the wireless components that worked fine before I updated to Yosemite.

Any other suggestions???