!" 1. #$%&' ()*+,-(./'0'12,34567/4898:;8 5( <#$%=>/ ?@ %A@ B 141 :. *. : C @ B ?8DA/4E%A+0'1FG:A*HD/'%A/%A+FG:AE*H IJ % A/%A+FK :A@ *. B *. /%./ JA/%A@ B '0'1 #$6LFM,N(O3-MFPQ:/;8)FAR9LE6L%MSMO TUVW#XYZ [\;0I#( <\;0I](;8^ _ ` ( 91 / B ( 85[( aA+bJcd e 8f/M,1' B ( g./'0'h1O( ( ) ( ) ( ) ( ) ( ) 5 5 3 2 5 4 3 2 5 4 3 2 2 3 4 5 5 10 10 . 5 10 10 5 x a x a x x a x a x a x x a x a x a xa a − = + − = + − + − + − + = − + − + − 85<(G:*HD/%./'JA/%Ai( 6 2 1 2x x − ÷ B ( ]HD/f/SMA/%A+98( ( ) ( ) 6 6 2 6 6 3 6 1 2 . 2 1 k k k k k k k C x x C x − − − − ÷ = − jG:%*(kc%lmF5,-%l< #5L*HD/3G:98n<om 4(# C /mpqopkmmpk 85( G:*HD/'eA/%Ai 10 2 x x + ÷ F:8A/%Ai,O*H:^IJ/j:63 B ( ]HD/'%?[A/%Ai98( 10 1 10 4 4 10 4 2 5 10 2 5 2 2 3360 Ëy 3360 k k k k t C x x t C x x x V t x − + − = ÷ ⇒ = = ÷ = 85o(&E*H B J < A/%A@ B ( ) 1 3 n x + 98pmrLG: B ( ]HD/'%?[j%Ai98( ( ) 1 3 k k k n t C x + = #5L*HD/'J < 98( ( ) 2 2 2 2 3 3 9 n n t C x C x = = g;8AO( 2 9 n C lpm 5n ⇔ = Bài tập 5. A/%A+Ib[?Jd O*HD/,398[F*HD/'98<oJF*HD/';98<e<J < rL G:48 B ( O ( ) 1 2 2 2 1 ax 1 ax . n n n C C a x + = + + + g;8AO( ( ) 1 2 2 2 24 24 1 252 252 2 3 8 n n na C a n n a C a a n = = ⇒ − = = = ⇒ = Ba ̀ i tâ ̣ p 6. G:*HD/'J I%A+bJhod e Giải : O*H/f/SM98l ( ) kkkkk k k xCxC −− − −=− ee e e e oo )()( _'J lseh%lls%l< #5L*HD/'J 98 << e o xC )( − lo<mmJ Ba ̀ i tâ ̣ p 7. G:*HD/%./'JA/%A+( [< + x x )98*HD/f/SMI%A+O 4(# C /mpqopkmmpk k k k k k kk k x x C x x CT − − − = = [< [< [< [< [< _%./'Jls[<h%l%ls%lk #5Ll p<o k [< = C P67(G:*HD/P/tA/%A+bJc<Ld [o j( _l[o98*Hu@*HP/^98*HD/'q lsl vvvvv [o op<pk< yxyxC −=− )( / B [(%A@ B *( d e b< dx + ;d k bo [dx − d e b dx − 6d [m [ b dx x + <(K :@ *. B J A/ *( d e b[ dx− ;d p [ b< dx x + d < [e [ b dx x + 6d <v < < b dx x − <(K :*. /%./ C J A/ *( d q < b dx x − ;d p < < b dx x − d < [e < b dx x + 6d m < < b< dx x − 4(# C /mpqopkmmpk 4(# C /mpqopkmmpk