i just wonder if sth like 50% x 8-10 , 60% x 5 , 75% x 5 would be better?
I mean is this sufficient warmup for 3 sets of 5 reps (same wieght each set)
?

For example my recent warmup for deadlift:
40kg x 10
60kg x 5
80kg x 3
100kg x 2
120kg x 5 reps x 3 sets WORKING SETS
and here for bench press
20kg x 10
40kg x 5
60kg x 3
84kg x 5 reps x 3 sets WORKING SETS
is sth like this okay?

i just wonder if sth like 50% x 8-10 , 60% x 5 , 75% x 5 would be better?
I mean is this sufficient warmup for 3 sets of 5 reps (same wieght each set)
?
I think the important question is how do your main working sets feel? Do you feel like you need more warm up? If you hit your first working set and your muscles are ready to go, then I'd say your warm up is fine.
I wouldn't worry about the particulars of warm up sets until you start hitting crazy numbers. Warming up for a 100kg deadlift does not need to be nearly as detailed as a warmup for a 300kg deadlift, as an example.
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for some time for main lifts i did sth like
5-8 x 50%
3-5 x 70%
1 x 80%
and it was fine i guess...

Warmups should never tire you out, only warm the muscles, tendons & ligaments and get your nerves & mind ready for the work sets. Generally older guys need more warmups and younger guys need less. For this reason, there are several versions of the 5x5 system. Some do 4 progressively heavier sets of 5 then one work set. Some do 3 progressively sets of 5 and 2 work sets, etc. I've known some people to even start with an empty bar. Only you can determine how many warmups you need in order to do justice to your work sets.
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