sorry my english is not enough good to explain.
but when i had X2 i was able to strech timing multiple tracks in the same time. now in X3 i can't anymore... 
how to fix it? tx
https://www.youtube.com/w...Q&feature=youtu.be

Try holding down the CTRL key while you drag the end of your clip.

same thing. 

The CTRL key is the default for slip-stretching. I just tried this in X3, and only the track actually being stretched will take the stretch.
 
I am unsure how to achieve this (or if possible), since the "Quick Group" functionality (using CTRL) may be overridden by the slip-stretch's CTRL.
 
Edit: The only way I am finding to do them both at once is to select both tracks and use "Length" in the clip properties, but this is clunky and only works if they had the same start times (cannot "visually" stretch them this way either).

i will try to copy paste it then.

I misunderstood. I thought PsychatoR was looking for that button in the control bar that changes dragging to stretching.
 
Here's a bunch of people complaining four years ago that X3 cannot do this: http://forum.cakewalk.com...-at-Once-m2263921.aspx
 
There was no solution found then, and I can't do it in Platinum, either.

Larry beat me to it (was about to check Platinum). My "hunch" is that the CTRL from quick groups loses functionality when the operation is using the CTRL key (so X3 and above may have lost this functionality).

I think the OP is mistaken that this worked in X2. My solution would be the same now as proposed in the thread that Larry linked: Slip-stretch the first clip, and then enable snapping to Clips in Landmarks, and slip-stretch the end of the other clip(s) to match.

ok it worked, i copy pasted the 1rst track to 2nd. 
i was worried about the automations but its all good. for now. surely later it will cause me problem with automations. but whatever, for now it work. tx guys. i hope they will fix this.

brundlefly
Slip-stretch the first clip, and then enable snapping to Clips in Landmarks, and slip-stretch the end of the other clip(s) to match.

 
But you still can't slip-stretch those clips simultaneously, no?