   !""#"$%"# #!&'! Câu I (2 đim) (&) *  *y x x mx= − + +, , -))./01&1234&)5 m = , 67-!489:&)+,;:.1&.:<=!9>9  !?!+@,A  ' x y − − = Câu II (2 đim) ,%-BC!6    ) + , ) + , ) D * E x x x Π Π + + + = − ,%-/7BC!6 ( )   F ! x x+ + ≥  !  x Câu III (1 đim) GGBH     xdx I x x = + + − ∫ Câu IV (1 đim) (6IB=!JK(LMJNKN(NLN;JKOJLO9PJJNO *  a 1&  DBAD∠ = M%Q1&#R&!:89JNLN1&JNKNM(=!S! J(N1T!!;1UVB?!+KLQ#,MG:G5;BJKLQ# Câu V ( 1 đim) ().@C!<PPWX9Y<ZZWOM6!4X 789/:=A    + , + , + ,x y z y z x z x y P yz zx xy + + + = + + Câu VI ( 2 đim) ,![I\< ABCV P !BH!!89!;J;BC!6  ' x y + − = M !9>9J;BC!6 E *  x y + − = 1&:(+E]*,M 69I^KM ,_0BC!6 !?!>9Q+]],1T!!;1&` !?!+@,& !90899VB?!;BC!6A '  x y z + + + = 1&   x y z− + + = Câu VII (1 đim) (59:            + , MMM * * x a a x a x a x a x + = + + + + +  + , k a R∈ "Y6)! k a U7M . = M%Q 1& amp;#R&!:89JNLN 1& amp;JNKNM(=!S! J(N 1 T!!;1UVB?!+KLQ#,MG:G5;BJKLQ# Câu V ( 1. ≥  !  x Câu III (1 đim) GGBH     xdx I x x = + + − ∫ Câu IV (1 đim) (6IB=!JK(LMJNKN(NLN;JKOJLO9PJJNO *  a 1& amp;  DBAD∠