Question

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Answer 1

$a, (x - 1) (x + 1) - 2 x + 2 = 4 < = > x^{2} - 1 - 2 x + 2 = 4 < = > x^{2} - 2 x - 3 = 0 < = > (x^{2} - 3 x) + (x - 3) = 0 < = > x . (x - 3) + (x - 3) = 0 < = > (x - 3) (x + 1) = 0 < = > x - 3 = 0 h o ặ c x + 1 = 0 < = > x = 3 h o ặ c x = - 1 V ậ y x = 3; x = - 1$

$b, (x + 1) (x^{2} - 3) + 2 x^{2} - 1 = 24 < = > x^{3} - 3 x + x^{2} - 3 + 2 x^{2} - 1 - 24 = 0 < = > x^{3} + 3 x^{2} - 3 x - 28 = 0 < = > x = 2, 536 (n g h ệ m x ấ u)$

$c, (x - 2) x + 4 = 2 x < = > x^{2} - 2 x + 4 - 2 x = 0 < = > x^{2} - 4 x + 4 = 0 < = > {(x - 2)}^{2} = 0 < = > x - 2 = 0 < = > x = 2 V ậ y x = 2$

$d, x (x^{2} + 3 x) = - 3 x - 1 < = > x^{3} + 3 x^{2} + 3 x + 1 = 0 < = > {(x + 1)}^{3} = 0 < = > x + 1 = 0 < = > x = - 1 V ậ y x = - 1$ .

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Answer 2

$a, (x - 1) (x + 1) - 2 x + 2 = 4 < = > x^{2} - 1 - 2 x + 2 = 4 < = > x^{2} - 2 x - 3 = 0 < = > (x^{2} - 3 x) + (x - 3) = 0 < = > x . (x - 3) + (x - 3) = 0 < = > (x - 3) (x + 1) = 0 < = > x - 3 = 0 h o ặ c x + 1 = 0 < = > x = 3 h o ặ c x = - 1 V ậ y x = 3; x = - 1$

$b, (x + 1) (x^{2} - 3) + 2 x^{2} - 1 = 24 < = > x^{3} - 3 x + x^{2} - 3 + 2 x^{2} - 1 - 24 = 0 < = > x^{3} + 3 x^{2} - 3 x - 28 = 0 < = > x = 2, 536 (n g h ệ m x ấ u)$

$c, (x - 2) x + 4 = 2 x < = > x^{2} - 2 x + 4 - 2 x = 0 < = > x^{2} - 4 x + 4 = 0 < = > {(x - 2)}^{2} = 0 < = > x - 2 = 0 < = > x = 2 V ậ y x = 2$

$d, x (x^{2} + 3 x) = - 3 x - 1 < = > x^{3} + 3 x^{2} + 3 x + 1 = 0 < = > {(x + 1)}^{3} = 0 < = > x + 1 = 0 < = > x = - 1 V ậ y x = - 1$ .

Answer 3

a, (x−1)(x+1)−2x+2=4<=>x2−1−2x+2=4<=>x2−2x−3=0<=>(x2−3x)+(x−3)=0<=>x.(x−3)+(x−3)=0<=>(x−3)(x+1)=0<=>x−3=0 hoặc x+1=0<=>x=3 hoặc x=−1Vậy x=3; x=−1a, x-1x+1-2x+2=4<=>x2-1-2x+2=4<=>x2-2x-3=0<=>x2-3x+x-3=0<=>x.x-3+x-3=0<=>x-3x+1=0<=>x-3=0 hoặc x+1=0<=>x=3 hoặc x=-1Vậy x=3; x=-1

b, (x+1)(x2−3)+2x2−1=24<=>x3−3x+x2−3+2x2−1−24=0<=>x3+3x2−3x−28=0<=>x=2,536 (nghệm xấu)b, x+1x2-3+2x2-1=24<=>x3-3x+x2-3+2x2-1-24=0<=>x3+3x2-3x-28=0<=>x=2,536 (nghệm xấu)

c, (x−2)x+4=2x<=>x2−2x+4−2x=0<=>x2−4x+4=0<=>(x−2)2=0<=>x−2=0<=>x=2Vậy x=2c, x-2x+4=2x<=>x2-2x+4-2x=0<=>x2-4x+4=0<=>x-22=0<=>x-2=0<=>x=2Vậy x=2

d, x(x2+3x)=−3x−1<=>x3+3x2+3x+1=0<=>(x+1)3=0<=>x+1=0<=>x=−1Vậy x=−1

2 câu trả lời 561

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