Yellow/browish leaves HELP!!

some of my plants started turning yellowish brown last night Ann others started turning light greenish yellow can anyone tell me what's going on ? Posting pictures as well

A picture of the whole plant would help more...

Maybe

Any more info? Like age soil ect...

Older leaves or new leaves? Different leaves may caused by different problems. Can you give a picture of the whole plant?

His plant probably died. Been over a month and no new info.