#1
Hi guys, im new to guitar and was hoping someone could help me figure this out. I noticed many songs with these 'x' signs on the tabs so i was wondering how do u play them together with the numbers. eg. the first one

3
3
4
5
x
3

i hear its something gotta do with muting the string or something like that.

than there is also the parts where the whole thing is:

x
x
x
x
x

how do u play that also?

lastly how to practice such movements? any songs which uses this technique alot so i can learn? If there was a previous thread that talks about this also could u please direct me to the link? i cant seemt to find any...
those were taken from 'cant stop' by red hot chili peppers.

--3---3-3--------
--3---3-3-x-7---
--4---4-4-x-7---
--5---5-5-x-7---
--x---x-x---5----
--3---3-3--------

Help Please! Thanks!
#2
alright, the single x means you play all of those other strings, but angle the first finger so that it touches the fifth string (muting it), while the fingertip still plays the note on the e string.
think of it like this...to play anote normally, your finger comes down perpendicular to the fretboard. to mute the string next to it, it'd hit at about a 45 degree angle, tilted inward.
to mute all of the string, lay a finger across all of the strings. put enough pressure to deaden the sound, but not enough to sound any notes. and unless you want to hear harmonics, avoid the fifth, seventh, twelfth, and fourteenth frets...you'll hear tones (sometimes a good thing), which won't get the crunchy, chunky sound you're going for.

to practice, start with your fingers completely off the neck. then just keep forming the chord, play each note individually to make sure you're not accidentally muting notes you want and that you're muting the "x". then give it a strum for good measure.
then take your fingers off the fretboard. and do it again. do it until you're nailing the chord without any adjustment the first time through.
this is a great way to memorize any chord, with or without muting.
once that's done, try to switch between this chord and any other chords you know, and switch back again. keep trying until you can do it smoothly and effortlessly.
#3
Alright man, to start off, the 'x' s are dead notes in which they don't sound at all. In your first example shown, i suggest a Barre Chord on the 3rd string with your ring finger on 5th fret on the d string BUT also make it so it touches the a string so no sound comes out of that note (from the barre on 3rd fret) then put middle finger on 4th fret on g string.

Next up, you have all the notes are 'x's that means no notes are being heard just place your left hand anywhere over the frets and strum it...thats basically it. (view the ending of Stairway to Heaven for a good example on this technique)