it depends
the open developer is likely darker than a light tea colour by now - if it is - chuck it.
The d76, like nmost dry developers, in sealed foil will last almost forever. I just mixed a can on D-19 last month that was sealed in a can in 1965. It is performing like it was new.
Pour the fixer into another container. Look for white/yellow particulate, mostly stuck to the original container. If you see it, you will smell the sulfur. If so, it has 'sulfated out', and should be discarded. Or store it to (once diluted) ferilize the garden in the spingtime. Without silver in it, fixer is just sulfu ( by now caked to the jug likely), soduim and ammonia.