Chuyên đề : Hệ phương trình mũ và logarit Giải các hệ phương trình sau 1) ( ) ( ) 3 3 4 32 log 1 log x y y x x y x y +   =  − = − +   2) ( ) ( )      >= = 0x 642 2 2 y y x x 3)        =+ =+ − 3 1 52 12 1 log log 2 2 5 2 y x x y y x 4)      = = +− 5 1 10515 2 xy y xx 5) ( ) 2 4 4 9 27.3 0 1 1 log log log 4 4 2 xy y x y x  − =   + = −   6) ) ( ) ( )      =+ =+ − − yx xy yx yx 2 2 69 12 2 2 7) ( )      =− = 2log 9722.3 3 yx yx 8)      =         − =+ 5loglog22 12 1 2 yx yx x y 9)      =+ = 68925 2002.5 2 2 3 3 y x y x 10)      =− =− − − 3 22.74 3 2 xy y y x x 11) ( ) 2 log 1 log log lg2 x y y x  + =   − =   12)      =− =− − − 3 22.74 3 2 xy y y x x 13) ( ) 2 2 1 l g 1,5 2 2 2 10 100 10 10 6 3 2 10 9 o x y x y x y + +  =    + =  + −   14) ( ) ( )      = + − + − + =+ −− 8 53 542 12 yx yx yx yx xyxy 15) ( ) ( )      −=+ =+ − yxyx yx xy 5 log3 27 5 3 16) ( ) ( ) ( ) yxyxyx +=−=+ 3 22 3 33 9 logloglog 17)    =− =+ 1loglog 4 44 loglog 88 yx yx xy 18)      +=++ =+ +−+ 113 2.322 2 3213 xxyx xyyx 19) ( ) ( ) ( )      =+++ =− 111 239 22 3log log 2 2 yx xy xy 20)      = = 182.3 123.2 yx yx 21)      = = −+ 1 2 99 yx yx yxyx 22) 3 1 2 3 2 2 2 3.2 3 1 1 x y y x x xy x + − +  + =   + + = +   23) 2 2 2 3 log log 1 log ( ) 1 xy y y x x y x  − =    − =  24) 2 2 4 4 4 2 4 4 4 log ( ) log (2 ) 1 log ( 3 ) log ( 1) log (4 2 2 4) log 1 x y x x y x xy y y x y  + − + = +     + − + − + = −  ÷     25) 1 2 2 (1 4 ).5 1 3 1 3 1 2 x y x y x y x y y y x − − + − +  + = +   − − = −   26)    =− =+ 1loglog 272 33 loglog 33 xy yx xy 27) Tìm m để hệ phương trình sau có 2 nghiệm phân biệt 2 3 3 3 2 2 ( 2 5) log ( 1) log ( 1) log 4 log ( 2 5) log 2 5 x x x x x x m − + + − − >    − + − =   . Chuyên đề : Hệ phương trình mũ và logarit Giải các hệ phương trình sau 1) ( ) ( ) 3 3 4 32 log 1 log x y y x x