Bài tập đại số lớp 9

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x 9) x x 1 x : A b/ x x 1) : x x : x x x x : x x Z : E a b/ a 4a a a a a a : a a a 1) a : F 4) a a a x x : x 1 x : K x 2 x x a : F x x x a a : x x x x 1; x 4) x x : x x x M x x 4) x x : x x x 9) x x x x ; x 9) x x : x 1) x x x x 4) = A x + x a a : a a c/ x a a 2 b 1 b 3 b 9) b b : N : A : a : D x Z :G 1) : H x x 4) a : D : I x x M 15 10 x x 15 a a 4) a : P x 2 x + 3a = x x x 4) :C : D x x 1 : x 1 : x Z x x 1; x 9) x x 1) x x x x :Q : R x x x x x x x 1) x x Q Q x x x x x 4; x 9) :T x x x : x x : x x x 49 x x M : x x x 10 x x 4) : S a2 : A a a a a a a a a 2x x x x 1) A A : K x x x x x 1 x x 1 x x : x x x 1 :C x x x x x x 1) : L x x x x x 1) x : B x x x x x : x 1 x 1) x L : E x : x x x 2) x : H x2 x x x x x x 0) : G a a a a a a a : N a2 a 2a a a a a a N : 2) 1) 2) 1) b/ 12 d/ 32 10 24 11 3 : 21 3 y= c/ t a/ a/ 5 2) b/ 125 45 180 : 2) c/ 14 10 35 d/ 12 2 2 3 2 : y= a/ 2) b/ 112 63 28 2) c/ 10 d/ 7 1; 3) 15 21 : x y= a/ 2) 2) 5 7 b/ 28 12 21 c/ 14 21 3 21 d/ : y= 3x b/ c/ 14 2) 10 2) 5) a/ d/ 3 17 17 34 2 : y=3 b/ (D2) 2 11 10 3 2 : 11 22 3 6 b/ 15 200 450 50 : 10 2) c/ 14 20 d/ x y= d/ 18 c/ a/ 2) 99 y=5 41 12 a/ 2) : 11 a/ 6 11 11 2) b/ 27 48 75 2) 4) c/ 5 2 d/ song song (d1 3 5 : y= x a/ b/ 12 23 15 2) 48 108 192 : 2) c/ 2 d/ 11 5 : y= x a/ 22 10 b/ 27 21 2 2) 2) c/ d/ 1 3x 3 2) 2) : a/ c/ 12 60 b/ 42 60 d/ 27 3 : b/ 2) 96 c/ 7 3 a/ 2) 12 112 y=1 d/ 175 51 10 2 15 10 6 10 6 15 1: 2: 80m 4m 195m2 m2 2x x x 2) x 2x 3) 4x 2x 4) 5x 1) y y 2y y 20 y 13 y 3y 2y 23 5) x 2y x 3y 6) 99 x y 17 5x y 5x 7) x y y 5 7y 3x 5 y 2x x y x 2y 3x y 2) x 2y 2x y 3) 4x y 2x y 4) 3x y 1) 20 13 13 5) x 2y x 3y 6) y 7x 2x y 2x 7) x y y 2 3y 2x y 2x 84m2 2x y x y 3x y 11 2) x y 20 1) x y 3) 3 x 3y 4) 5) x y 11 5x y x y 2x y 6) 4x x 3y y 2x x 3x 2) 4x x 3) 3x 1) 3y 4y 2y 3y 12 y 2y 4) x y x 3x y 5) 3x 2y x y x y 6) x y 2 1) x 11y 10 x 11y 31 4) x y 7x 3y x x y 1) 2x y 9x y 4) sau: x y y 3x y y 2) x 0,5y 2x y 5) 5x 5)x (1 2x y 3) x y y 2) y x y 2 y 2 6) x 5) x y 3) 3x y 2x 3y x y x 6) 5y 5x y 5 : 2 2: 1) x y 10 x 2y 4) 2) 5) x y 3) 14 5x y 6) x y 11 y x y 31 y 2: x y 13 1) 4x y x 3y 2) 2x y 4x 3y 2 3 2x y 3 x y x y 2x 3y 2) 5x y 1) y x 3) x y 15 12 4) 5) x 2y 3x y 2 2 x y x 2x y 3x y x 5) 2y x x y 3) 5x y x x 3x 2) 2x 1) 12 x 3y 3 y 6) x y y y 13 2y 12 4y 4) 5) 2y 2,3 3) 3y x 0,8 x y xy x y xy 2x y 3x y 3x 6) y 4y x 2x y x 3y 2x y x 3y 3x 2x x y 4) 6) 3 3x 2 y 2x y 20 H : 54 1) x 3y 2) 3x y x 3) y x y 10 4) 5) x 3 x y x x 3y 2 2x 6) y y 3x 2 y 2x 3 y x 3x 3x 2) 6x 1) y 2y 2y y 2x y 3) x y 10 4) 5) 6) x y x y x y x y 5x y x 5y x y x 2y 11 100 10m2 1) 2) 3x 3) 5x 5) 7y 41 3y 11 x 3y x 2y x 2y x y 12 x 2y 4) 5 x y x y x y x y 15 6) 2x y 3x y 13 y 3x 10 2) 18 x 32 y 40 5) 3x y 3x 6) 3y 3x 3y 3x 3y 2x y 3x x 2x 2) x 3) ,n 60m2 6) y x 12 x y 2y 11 2x y 10 x 5) x 2y 2x y 6) 2 6x y 2x y 3y 5 12 5s 3t s 3t s t t ,n 2m 42m2 4) 2x 3y 5) 5x y x y x x y x xy y x y y x y 2 xy x 2y x y 3x y 2) 2x y 1) 2x y 3x y 3) x 4021 4021 x y hai y y 3y y 3s 2t 4) s 3t y x y 4) 4y 5y 3y x y x y 2x y 12 4) x y x 2x 2x 2) x 2011x 2010 y 2010 x 2011 y 3) x 2 3y 5) 2x 3y 1) 5x y 1) x x y 18 2 1) 3) y 17 8m2 y x y 13 3y x 18 2) y 10 x 1) 99 21 3) x 2y 4x 3y 4) 2x 3 y 2x 6y 5 2 x y x y 5) 2x y 6x y 2mx 1: a/ hai ng A t x1, x2 A = x12 x 22 x12 x x1x 22 (x1 x ) x1 x 11: Cho x2 4x + m a/ 1> 3x m 2: x1 x2 x2 A a/ 1, x2 a/ x13 x 32 27 3: Cho x2 (m 1)x m = x1, x2 a/ x1, x2 A B 4: x x x12 x22 12: Cho x2 mx + m 2 x12 x1 x2 x22 2x m2 + 4m x1 x2 x1 x2 x12 x22 x1 x2 13: Cho x2 a/ t x1, x2 x12 x 22 4x1x A x13 x 32 2mx 3m2 + 4m 5: 1)x 14: m a/ hai m x1, x2 x1, x2 A 6: C A x12 x2 x1 x (2m + 1)x + 15: Cho x2 2x + m a/ a/ x1, x2 :x x1, x2 7x1x x12 x 22 (2m 1)x + m2 m x12 x 22 x12 x 22 3x1x 16: Cho x2 (m + 2)x + m a/ x1 ; x2 R = 6x1x2 x x (m + 2)x m b/ : Cho 2 x1, x2 a/ 1, x2 b/ : x2 x1 x22 3x1 x2 A = x12 x x1x 22 6x m2 + 8m = x x22 17: Cho 2(mx + 1) x2 1, : Cho x x2 x x (2m 1)x m2 x x1 x2 x22 18: Cho x(x 2m) = 2 x1, x2 x1, x x1 , x 2 x1, x2 A 10 A x13 x 32 = K x 48 x x1 x2 2 2mx 19: : Cho x2 2mx + m2 m + = 4m a/ 1, 20: x2 a/ b/ x1, x2 2 A x x x1 x2 (2m 1)x + m2 x1 ; x2 a/ x b/ 21: 2m x2 (2m A x1 x2 x1 x2 : Cho x2 (2m + 3)x + m2 + 3m + = x1 ; x2 a/ x : Cho x2 b/ b/ 2m x2 17m x1, x2 a/ Ch R x1, x2 : Cho x2 4x + 5m2 + 2m = 1x2 4x1 = 23: a/ x1 x2 x=- b/ x13 x23 35 x1, x2 24: Cho 3(mx + 1) x2 x : Cho x2 2(m x 18 x1 x2 1, x2 1, x2 2 x 8=0 x 2 1)x + m2 x1 x 4m 1=0 1, x2 x1x x12 x 22 x22 : Cho x2 25: Cho x2 (m + 1)x m x1, x2 P x12 x : Cho x2 2(m + 4)x + m2 x1, x2 A x1, x2 x22 x1 x2 3x1 3x2 A x x x1 x2 2 26: Cho x2 : Cho 2(mx + 1) x1, x2 x2 1, x2 2 x x 27: Cho x2 (m 1)x + 2m x1, A x12 x1 x22 x2 2 x12 x22 : Cho x2 4x + m = x2 x1 x2 x2 x1 : Cho x2 2x + m = a/ 3x1 2x2 = : Cho x2 2(2m + 1)x + 3m2 + 6m = x2 3x1 x2 1, A x12 x22 x12 x22 1, 2m x2 x2 m2 : Cho x2 + 3x + m = x1 x x12 x1 x22 x2 14 x1 = 2x2 (2m 3)x + m2 2m + = c x1, x2 5x = 16 2x 2m2 x1, x2 a/ : Cho x2 x1, x2 1, a/ : Cho x2 : Cho x2 + (2m 1)x + m2 = A x12 x1, x2 x2 32 x x2 x12 x22 : Cho x2 : x2 a/ x1, x2 a/ R x x 17 : Cho x2 2mx + m2 m b/ x1; x2 x1 x2 : 4x + 2(3 2m)x + m2 3m + = x1, x2 x1 x2 : Cho x + 2mx 2m a/ b/ :x a/ b/ x1, x2 x1 x2 x22 2(m + 1)x + m + 3m x12 x 22 x1x : (m 1)x2 2(m : x 2 2m x 3m2 2=0 1, x2 22 m 1) a/ a/ 1, R x22 x1 x2 : x2 2(m 1)x + m2 a/ nh nh t 3m A=x1x2 + 2x1 + 2x2 1, x2 320m2 4m 1: = 0, (3m 2)x 5x2 = 50: m b/ x b/ c/ x1 ; x2 b/ x12 ? 2: 3: 4: 5: 6: 7: 128m2 chu vi 140m c 1176m ao 5/3 2/3 280m 240m 150m2 8: 000 sau v 12: 286.650.000 ? ? a/ 2x 5x = c/ x x d/ 4x4 b/ x 15 4x + 20 = c/ x 12x2 + = 2: Cho (P) : y = 1: a/ 2x2 + 5x x x 2 (D) : y = x d/ 9x4 b/ x2 2x + = 7=0 15 12x2 + = 2: Cho (P) : y = 3: Cho x2 2mx + m = x2 (D) : y = x 2 3: Cho x2 3mx + 3m = a/ a/ x1, x2 x1 x2 , x1 x2 , x12 A= x m x2 theo m x1, x2 x1 x2 , x1 x2 , x12 24 x x1 x2 A= 2 1: a/ 4x2 + 9x = c/ x2 + x = 12 b/ 2y = d/ 3x2 2x + = f/ x x x 10 x x 4 x2 mx + m = m 3x2 x2 (P) : y = 2: a/ 3: x 1, g/ 3x 2x 20 = 2x x2 x h/ x x x (P) : y = a/ x2 x f/ x g/ x 3x = x2 x x h/ 3: Cho x2 b/ 3x2 + 5x + = d/ 3x2 2(x + 1) = e/ x 2 2: a/ 24 x x1 x2 2 1: a/ 2x2 3x = c/ (x + 2)2 = x e/ x 2 m x theo m 2 2mx + 2m = 1, x2 theo m theo m A = x1x x12 x 22 A = x1x x12 x 22 1: x + 27x = c/ 9x2 = 4(3x 1) b/ 4a4 9a2 = a/ e/ x d/ x2 + x = x 1: x2 = a/ x3 c/ (x 3)2 = 10 4x e/ x f/ x2 b/ 9t4 = d/ x2 = 2(3 + x ) 3 x 6 x x2 f/ g/ 3x2 + = 4x4 h/ x x x 10 g/ 9x4 + 8x2 = x 10 x h/ x x2 2x 2: a/ 2: a/ x2 v (D) : y = 3x + (P) : y = (P) : y = x 2 (D) : y = x + 3: (m + 2)x + m + = 3: Cho x2 2x m2 = 1, x2 x1 , x theo m theo m x1 c/ x12 x2 1(x1 1: a/ 4b2 5b = c/ x2 + 2x 63 = e/ x 2) + x2(x2 2) 1: a/ 2c2 = b/ 3x x = d/ 7x2 + = 2x f/ x 2 x f/ x x g/ (2x2 1)2 = x2 + 2(x4 1) x h/ x x x2 2: Cho (P) : y = (D) : y = x (P) 3: Cho x2 + mx + 2m = a/ C b/ 2x2 x = c/ 3x2 = 21 2x e/ 3x x22 3x1x2 = 10 x1 x2 d/ x2 x x 5x + + =0 g/ 3(x4 + 1) = 10x2 14 h/ x x 2: Cho (P) : y = x (D) : y = x + 2 a/ b/ A(2 ; 1) 1, x2 + mx + m 3: Cho x2 1=0 a/ C 1, x2 theo m i m = theo m c/ e/ x12 x x1x 22 x1 2x1x2 + x2 = 1: a/ 7x 42x = c/ 2(3x + 4) = 5x e/ x 2 b/ x d/ 6x 2 x =0 2x 1=0 1: a/ 36x4 49 = c/ = 2x(2x 1) b/ 2x2 6x = d/ 5x2 3(2x 3) = e/ x 21 x f/ x2 x f/ 2 g/ (5x + 2) = 3(10x + 1) 16 30 h/ x x x2 (P) : y = 2: (D) M 3: x2 x g/ x 29x + 100 = x x x x h/ 3 2: (D) song x x2 song (d): y = (P) : y 2 3: Cho x2 2mx + m = 3mx + 3m = x1, x2 b/ theo m c/ x1, x2 x1, x2 theo m c/ d/ x2 theo m x12 x 22 5x1x 18 24 d/ 1: a/ 2x2 2x = c/ x2 = 6(x 1) 1: 18 = b/ x 2 d/ 4x 4x + = e/ x 2 f/ x x2 5x f/ 3: theo m d/ x1, x2 th x12 x 22 x1x 2 1: a/ 25x 2 (2m 1)x m = b/ 16x4 25x2 = ) = 11 d/ 2x(x a/ x x = c/ 2x2 + 5x = e/ x 2 a/ b/ M g/ 3(x2 + 18) = x4 12 h/ x x x2 2: Cho (P) : y = (d) : y = x a/ x1, x2 x2 x1 x2 x1 x x2 3 x g/ 5(x4 1) = 24x2 x h/ x x x2 2: Cho (P) : y = (D) : y = x + a/ b/ -4 3: ng + (2m 1)x + 3m = a/ x1, x2 theo m c/ x1, x2 d/ x12 x 22 x1x 1: a/ 7=0 b/ x4 + 11x2 = b/ x=0 c/ 4x2 5(4x 5) = d/ x2 2 = 2x d/ x2 6x + = 3x e/ x 16 = c/ 3(x2 + 4) + 5x = 3x e/ x 2 f/ x2 2 x f/ x 2 g/ x = 8(x + 6) x x h/ x2 2: Cho (P) : y = 2 g/ 3x (3x + 2) + = x h/ 2 x x x x2 x x2 2: Cho (P) : y = x x 2 x 2 a/ a/ b/ Cho A -2 (4m + 1)x + 2(m 4) = : (m + 5)x m a/ b/ c/ x -3 B i (P) 3: Cho 1, 1, x x x1x x2 theo m i m = x2 ph 1, x2 2 1, x1 x2 65 x2 theo m