I need help on 7th gym leaders, liza and tate.They have Claydol,Xatu,solrock,and lunatone.Xatu and Claydol are lvl41,And solrock and lunatone are lvl42.I have a levle 51 blazaken,lvl 30 keckleonlvl27 sandshrew, and lvl28 vulpix.What should i do? I ve tried 12 times, and still have not beat them!

First you must train your Pokemon. Your strongest Pokemon is Blaziken, which is weak to Ground and Psychic attacks -Tate & Liza specialty-, so you must train a Water, Grass, Ghost or Dark Pokemon if you want to win.
The rest of your team won't do because Keckleon keeps changing its type, Vulpix is weak to Rock attacks and Sandsdrew is weak to Solrock's SolarBeam and all Tate & Liza's team is immune to Ground attacks.

As for a Pokemon that you could train, I recommend you a Sharpedo because it's Dark Type -immune to Psychic attacks- and, even if it doesn't learn any water attack, it learns Crunch which IIRC is the strongest Dark move in R/S/E.
Try to KO Solrock while it recharges/uses Sunny Day for SolarBeaming Sharpedo.

How about , or other speedy Water-type Pokemon?

Surf can take down three of the four Pokemon in Tate&Liza's team (it's super effective against , and ) and Ice Beam can take down the other one (it's super effective against ).

So all you need is a couple of quick Water Pokemon which know those two moves. I creamed Tate&Liza with my and (note that my knows Bite, and also Thunderbolt which knocked out in one hit).

first you should change your pokemon party. try having train them until level 40 or above and remember to give surf to . he is your key to win the battle.

Use ice-type pokemon. Try catching some in shoal cave, train it into , make sure it learn ice beam. It will KO and . For and , use with its water spout move.

yes i to am having problems with the pair i also have a Blaziken as my top pokemon and it's annoying always losing

You must have water/ ice type pokemon.....
Train your pokemon level

Take out and with a steel and a rock move works wonders.

a medicham would do good but my lombre is pretty good if you have one.

Hmm... A ? No, is a psychic/fight type which can be easily defeated by .

get a mightyena at lvl 40 cuz with its intimidate it will weaken earthquake enough for you to survive.

Intimidate is a good strategy...but Mightyena is NU. Try Gyarados with Intimidate