Bài tập luyện tập Đại số Lớp 9

Nội dung text: Bài tập luyện tập Đại số Lớp 9

1. Bài 1 : Tớnh (ruựt goùn): 1/.( 7 2)( 7 2) 2/. (5 2 3)(5 2 3) 3/.(7 2 3)(7 2 3) 4/. 2 3 + 4 3 - 2 15 5 5 2 5 6 2 5 1 5/. 6/. ( ) : 3 1 2 5 4 1 3 5 5 2 7 7 7 7 7/. 1 1 8/. 14 - 7 15 - 5 1 A = + : 1 7 1 7 2 -1 3 -1 7 - 5 3 3 21 7 9/.(3 )( 2) 10/. 5 5 15 3 3 2 1 3 7 1 5 3 15 5 5 2 5 11/. 12/. 3 6 21 15 + 1 + 1 3 1 2 5 4 2 3 7 5 2 3 3 2 2 2 3 3 2 3 2 2 13/. 13/. 3 2 6 1 2 3 3 2 1 2 3 6 18 2 2 14/. ( 3 3) 15/. 3 2 2 2 2 2 2 3 2 2 3 5 - 2 6 3 4 19 8 3 16/.6 17/. 8 2 2 2 3 2 2 3 18/. 19/. (7 4 3) : 3 2 2 2 3 6 3 5 5 2 6 2 5 1 20/.( ) : 21/. ( ) : 2 1 5 1 5 3 1 3 5 5 2 6 2 5 5 1 a 2 a 3a a 22/.( ) : 23/. (3 )(3 ) 1 3 1 5 2 5 a 2 3 a 1 a 3 a 5 a ab a 4 a 4 4 a 24/. 2 2 25/. a 3 b 5 a 2 a 2 9 a 9 6 a a a a a a 26/. 6 27/. (1 )(1 ) a 3 a 3 1 a a 1 Bài 2 : Tớnh (ruựt goùn): 2 2 2 2 1/. 4 15 15 3 2/. 3 2 2 2 2 4 3/.(2 5) 2 14 6 5 4/. ( 5 3)2 9 4 5 2 2 3 2 2 2 - 2 3 - 3 4 2 3 5/. 6/. 4 2 3 (1 3)2 7/. 8/. 2 3 4 7 4 3 9/.14 8 3 21 12 3 10/. 5 2 6 5 2 6 11/.7 2 10 7 2 10 12/. 4 2 3 12 6 3 13/.14 6 5 14 6 5 14/. 17 12 2 9 4 2 1
2. 15/.4 2 3 7 4 3 16/. 6 4 2 3 2 2 17/.8 2 7 +9 4 2 18/. 3 2 2 11 6 2 19/.11 4 7 16 6 7 20/. 11 4 6 11 4 6 21/.29 12 5 29 12 5 22/. 8 2 15 23 4 15 23/.8 2 15 48 6 15 24/. 49 5 96 49 5 96 25/.15 6 6 33 12 6 26/. 16 6 7 64 24 7 Bài 3 : Tớnh (ruựt goùn): Đưa thừa số ra ngoài dấu căn 5 2x 2 8x 8 1/.3a 2 ( Với a 0 ) 2/. (x>-2) a x 2 3/. 3 75 27 4/. 12 27 3 75 5/.7 24 150 5 54 6/. 2 28 3 63 5 112 7/.2 20 50 3 80 320 8/. 2 32 3 72 7 50 2 9/.32 50 98 72 10/.224 – 254 + 36 –150 11/. 2 5 125 80 605 12/.125 – 220 – 380 + 445 13/.32 – 418 + 232 –50 14/.548 – 427 – 275 + 108 15/.–250 +18 – 380 + 245 16/. 2 28 3 63 175 17/.228 + 218 + 232 –50 18/. 2 18 3 8 4 32 19/.36 – 463 – 3175 +112 20/.612 –20 – 227 + 125 21/. 8 3 32 72 22/. 6 12 2 48 5 75 7 108 23/.5 3 3 48 5 20 - 9 5 24/. 5 - 48 + 5 27 - 45 1 25/. 20 3 45 6 80 125 26/. 2 5 125 80 5 27/.3 2 8 50 4 32 28/. 27 2 3 2 48 3 75 29/.3 3 75 2 12 147 30/.20 2 45 3 80 125 31/. 2 128 162 200 6 98 32/. 242 288 5 2 3 338 1 2 5 33/.2 2 32 450 392 34/.10 72 162 128 2 50 98 3 7 3 35/.450 392 338 242 288 36/. 2 18 4 27 3 45 6 32 5 48 3 20 1 3 12 7 1 37/.162 128 338 288 38/. 18 2 45 72 3 20 9 4 13 24 3 3 4 1 39/.5 12 2 48 6 75 108 40/. 2 147 192 243 300 32 18 10 1 1 1 5 1 3 1 41/. 108 75 363 12 42/. 48 363 147 192 2 15 22 8 33 14 4 3 7 9 11 1 43/.12 75 300 108 44/. (5 48 3 27 2 12) : 3 2 5 10 6 5 45/. 8 3 2 25 12 4 192 46/.2 10 12 2 5 3 3 5 48 47/. (5 2 2 5) 5 250 48/. 2 112 5 7 2 63 2 28 7 49/.(2 3 3 2) 2 3 96 50/. ( 2 3) 2 24 2
3. 24 2 48 - 2 2. 14 - 8 + 63 52/. 12 48 108 192 : 2 3 51/. 8 53/. 2 27 3 48 3 75 192 3 54/. 2 3 2 2 32 6 4 2 2 3 6 1 55/.48 2 135 45 18 56/. ( 1). 8 2 2 6 Đưa thừa số vào trong dấu căn : a b 1 1/. (a 0,b 0 ) 2/.3 12 b a 3 3/. (2 3) 2 3 (2 3) 2 3 4/. (4 15) 4 15 (4 15) 4 15 5/. ( 35 6) 6 35 (6 35) 6 35 Bài 4 : Tớnh (ruựt goùn): 18 12 2 3 1/. 2/. x 2 3 3 2 2 5 1 3/. x 4/. x 2 5 2 2 3 5 3 7 5/.( ) 15 6/. 5 3 7 3 16 1 4 1 9 1 7/. 2 3 6 8/. 75 5 1 2 27 3 27 75 3 2 3 1 1 8 32 18 9/.6 5 14 10/. 18 0.5 3 75 9 25 49 3 8 1 4 36 4 1 1 3 2 4 1 11/. 2 12/. ( 4,5 50) : 13/. 2 27 75 3 2 2 2 5 15 8 1 1 4 3 48 5 2 75 5 1 14/. 2 27 6 75 3 3 3 5 4 25 1 15/.12 3 18 16/. 72 4 32 162 3 27 2 1 5 5 3 2 3 2 17/.20 5 18/. ( 6 2 4 )(3 12 6) 5 5 2 3 2 3 1 1 3 4 1 15 6 3 19/.( 2 200) : 20/. (2 )( 2) 2 2 2 5 4 35 14 7 1 3 - 3 1 10 21/. 27 - 6 + 22/. 20 5 3 3 5 2 1 30 1 54 1 50 - 2 96 - + 12 3 50 - 2 75 - 4 - 3 23/.5 15 6 24/. 3 3 1 3 2 1 3 3 25/.24 6 26/. 48 6 6 3 3 3 3
4. 1 1 1 1 27/. 28/. 5 2 5 2 2 1 2 1 3 3 2 2 29/. 30/. 3 1 3 1 5 2 5 2 1 1 1 1 31/. 32/. 1 5 1 5 3 2 2 3 2 2 2 2 1 1 33/. 34/. 3 2 2 2 2 3 5 2 6 5 2 6 1 1 1 6 2 4 35/. 36/. 175 1 2 3 1 2 3 8 7 3 2 1 1 2 1 3 2 37/.3 38/. 3 3 2 2 1 3 2 Bài 5 : Tớnh (ruựt goùn): x 1 x 1 x x 2x 4 x 8 B = . (x > 0; x ≠ 4). (TS 08-09) x 4 x 4 x 4 x x y x y x xy B = : (TS 09-10) 1 xy 1 xy 1 xy x x 2x 28 x 4 x 8 B (x 0, x 16) (TS 11-12) x 3 x 4 x 1 4 x 1 2 x 1 A với x > 0; x 1 (TS 12-13) x x x 1 x x x 3 x 3 A . (TS 13-14) x 3 x 3 x 9 x 1 2 6 B : 1 (TS 14-15) x 3 x x 3 x x 3 x x x 1 x 10 A (x 0, x 4) (TS 15-16) x 2 x 2 x 4 Bài 6 : Giải phương trỡnh : B 0vàA 0 A B Dạng 1 : 2 A B 4x 3 2x 0 4x 2 2x 1 5 x 3 2 x 5 3 2x 3 7 x 2 2x 2 x 2 3x 1 4 3x 6 2 3 5x 1 2 3 x 4x 9x 6 2 2 - 4 - x 0 x 1 3 2 3 - 4 + 8x 0 2x 3 13 2x 3 2 x 1 2 2x 15 3 5 2x 9 2x 3 3 x 4
5. 5 1 2x 1 2 1 6x + 6x + 24x = 2 3 3 2 3x 4 3x 25 3 3x 0 3 2x 5 8x 20 18x = 0 5 4x 8 2 9x 18 0 4 x 4 x 1 9 x 9 16 1 16x 16 9x 9 1 9x 9 16x 16 32 4 4x 4 + 9x 9 = 5 2 25x 25 - 16x 16 = 3 2 16x 16 9x 9 4x 4 x 1 8 5 4x 8 2 9x 18 0 x 1 9x 9 2 6 x2 4x 3 x 1 4 x 5 x2 2x 4 x 5 0 4x 20 3 x 5 4 9 2x 3 3 x x 12 18 x 8 27 a) x2 2x 1 1 x – 5x 2 = - 2 b) 2x 8x 12 Dạng 2 : B 0 A B A BhayA B 2 2 4 x + 5 6 4(x 2)2 8 4 1 - x 3 = 1 9(x 2)2 + 5 8 x 2 6x 9 3 x 2 8x 16 2 x2 2x 1 7 4x2 4x 1 3 9x 2 6x 1 3 b) x2 6x 9 5 x2 2x 1 x2 1 x 2 6x 9 3x 1 4x 2 12x 9 x 1 x 4x 2 4x 1 2 4x2 20x 25 1 25x2 30x 9 x 7 x2 2x 1 2x 5 x2 6x 9 2(x 1) 9x 2 12x 4 = 5 (3 2x)2 6 x2 2x 1 2 Dạng 3 : A 0vàB 0 A B A B 3x 2 x 6 x 3 2 x 2x 1 x 2 2 x 4 x x 5 x 2 4x 20 3 1 x 9x 18 4 1 x 9 4 Dạng 4 : 5
6. A B A B x2 2x 1 x2 6x 9 0 6