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23 tháng 7 2020

Trả lời:

\(\left(x^2-3x+2\right)^3=x^6-\left(3x-2\right)^3\)

\(\Leftrightarrow\left[x^2-\left(3x-2\right)\right]^3=x^6-\left(3x-2\right)^3\)

\(\Leftrightarrow\left(x^2\right)^3-3.\left(x^2\right)^2.\left(3x-2\right)+3.x^2.\left(3x-2\right)^2-\left(3x-2\right)^3=x^6-\left(3x-2\right)^2\)

\(\Leftrightarrow x^6-3x^4.\left(3x-2\right)+3x^2.\left(3x-2\right)^2-\left(3x-2\right)^3=x^6-\left(3x-2\right)^3\)

\(\Leftrightarrow3x^4.\left(3x-2\right)-3x^2.\left(3x-2\right)^2=0\)

\(\Leftrightarrow3x^2.\left(3x-2\right).\left(x^2-3x+2\right)=0\)

\(\Leftrightarrow3x^2.\left(3x-2\right).\left(x^2-x-2x+2\right)=0\)

\(\Leftrightarrow3x^2.\left(3x-2\right).\left[x.\left(x-1\right)-2.\left(x-1\right)\right]=0\)

\(\Leftrightarrow3x^2.\left(3x-2\right).\left(x-1\right).\left(x-2\right)=0\)

\(3x^2=0\Leftrightarrow x^2=0\Leftrightarrow x=0\)

\(3x-2=0\Leftrightarrow3x=2\Leftrightarrow x=\frac{2}{3}\)

\(x-1=0\Leftrightarrow x=1\)

\(\Leftrightarrow x-2=0\Leftrightarrow x=2\)

Vậy \(x\in\left\{0,\frac{2}{3},1,2\right\}\)

23 tháng 7 2020

\(\Leftrightarrow x^6-9x^5+33x^4-63x^3+62x^2-36x+8=x^6-\left(3x-2\right)^3\)

\(\Leftrightarrow x^6-9x^5+33x^4-63x^3+66x^2-36x+8=x^6-27x^3+54x^2-36x+8\)

\(\Leftrightarrow-9x^5+33x^4-36x^3+12x^2=0\)

\(\Leftrightarrow-3x^2\left(x-2\right)\left(x-1\right)\left(3x-2\right)=0\)

\(\Leftrightarrow x^2\left(x-2\right)\left(x-1\right)\left(3x-2\right)=0\)

\(\Leftrightarrow x=\left\{0;2;1;\frac{2}{3}\right\}\)

10 tháng 7 2019

\(1,\)\(\left(2x+3\right)^2=4x^2+12x+9\)

\(2,\)\(\left(3x+2y\right)^2=9x^2+12xy+4x^2\)

\(3,\)\(\left(3a-1\right)^2=9x^2-6x+1\)

\(4,\)\(\left(a-2\right)^2=a^2-4a+4\)

\(5,\)\(\left(1-5a\right)^2=1-10a+25a^2\)

\(6,\)\(\left(x-4\right)^3=x^3-12a^2+48a-64.\)

\(7,\)\(\left(x^2-2y\right)^2=x^4-4x^2y-4y^2\)

\(8,\)\(\left(5x^2-2\right)\left(5x^2+2\right)=25x^4-4\)

\(9,\)\(\left(2a^2-7\right)\left(2a^2+7\right)=4a^4-49\)

\(10,\)\(\left(x-1\right)\left(x^2+x+1\right)=x^3-1\)

\(11,\)\(\left(x^3-2\right)\left(x^6+2x^3+4\right)=x^9-8\)

\(12,\)\(\left(3x+2\right)\left(9x^2-6x+4\right)=27x^3+8\)

\(13,\)\(\left(x^2+3\right)\left(x^4-3x^2+9\right)=x^6+27\)

10 tháng 7 2019

1, ( 2x + 3 )2 = 4x2 + 12x + 9

2, ( 3x + 2y )2 = 9x2 +12xy + 4y2

3 ( 3a - 1 )2 = 9a2 - 6x + 1

4, ( a - 2 )2 = a2 - 4a + 4

5, ( 1 - 5a )2 = 1 - 10a + 25a2

6,  ( x- 4 )3 = x3 - 12x2 + 48x - 64

7, ( x2 - 2y )2 = x4 - 4x2y + 4y2

8, ( 5X2 - 2 ).( 5X2 + 2 ) = 25X2 - 4

9, ( 2a2 - 7 ).( 2a2 + 7 ) = 4a4 - 49

10, ( x - 1 ).( x2 + x + 1 ) = x3 - 1

8 tháng 10 2021

\(d,\Leftrightarrow x^3-6x^2+12x-8-x^3+27+6x^2+12x+6=15\\ \Leftrightarrow24x=-10\Leftrightarrow x=-\dfrac{5}{12}\\ e,\Leftrightarrow x^3-3x^2+3x-1+8-x^3+3x^2+6x=17\\ \Leftrightarrow9x=10\Leftrightarrow x=\dfrac{10}{9}\\ f,\Leftrightarrow9x^2+18x+9-18x=36+x^3-27\\ \Leftrightarrow x^3-9x^2=0\Leftrightarrow x^2\left(x-9\right)=0\\ \Leftrightarrow\left[{}\begin{matrix}x=0\\x=9\end{matrix}\right.\)

a: Ta có: \(3\left(2x-3\right)+2\left(2-x\right)=-3\)

\(\Leftrightarrow6x-9+4-2x=-3\)

\(\Leftrightarrow4x=2\)

hay \(x=\dfrac{1}{2}\)

1 tháng 10 2021

giải phần còn lại giúp mình được ko?

11 tháng 7 2021

Sửa lại môn học để các bạn làm nhé em!

11 tháng 7 2021

bạn sửa lại môn hôn học đi ạ

9) Ta có: \(\dfrac{2x+5}{x+3}+1=\dfrac{4}{x^2+2x-3}-\dfrac{3x-1}{1-x}\)

\(\Leftrightarrow\left(2x+5\right)\left(x-1\right)+x^2+2x-3=4+\left(3x-1\right)\left(x+3\right)\)

\(\Leftrightarrow2x^2-2x+5x-5+x^2+2x-3-4-3x^2-10x+x+3=0\)

\(\Leftrightarrow-4x=9\)

hay \(x=-\dfrac{9}{4}\)

10) Ta có: \(\dfrac{x-1}{x+3}-\dfrac{x}{x-3}=\dfrac{7x-3}{9-x^2}\)

\(\Leftrightarrow\dfrac{\left(x-1\right)\left(x-3\right)}{\left(x+3\right)\left(x-3\right)}-\dfrac{x\left(x+3\right)}{\left(x-3\right)\left(x+3\right)}=\dfrac{3-7x}{\left(x-3\right)\left(x+3\right)}\)
Suy ra: \(x^2-4x+3-x^2-3x-3+7x=0\)

\(\Leftrightarrow0x=0\)(luôn đúng)

Vậy: S={x|\(x\notin\left\{3;-3\right\}\)}

11) Ta có: \(\dfrac{5+9x}{x^2-16}=\dfrac{2x-1}{x+4}+\dfrac{3x-1}{x-4}\)

\(\Leftrightarrow\dfrac{\left(2x-1\right)\left(x-4\right)}{\left(x-4\right)\left(x+4\right)}+\dfrac{\left(3x-1\right)\left(x+4\right)}{\left(x-4\right)\left(x+4\right)}=\dfrac{9x+5}{\left(x-4\right)\left(x+5\right)}\)

Suy ra: \(2x^2-9x+4+3x^2+12x-x-4-9x-5=0\)

\(\Leftrightarrow5x^2-7x=0\)

\(\Leftrightarrow x\left(5x-7\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x=\dfrac{7}{5}\end{matrix}\right.\)

12) Ta có: \(\dfrac{2x}{2x-1}+\dfrac{x}{2x+1}=1+\dfrac{4}{\left(2x-1\right)\left(2x+1\right)}\)

\(\Leftrightarrow\dfrac{2x\left(2x+1\right)}{\left(2x-1\right)\left(2x+1\right)}+\dfrac{x\left(2x-1\right)}{\left(2x+1\right)\left(2x-1\right)}=\dfrac{4x^2-1+4}{\left(2x-1\right)\left(2x+1\right)}\)

Suy ra: \(4x^2+2x+2x^2-x-4x^2-3=0\)

\(\Leftrightarrow2x^2+x-3=0\)

\(\Leftrightarrow2x^2+3x-2x-3=0\)

\(\Leftrightarrow\left(2x+3\right)\left(x-1\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{3}{2}\\x=1\end{matrix}\right.\)

15 tháng 10 2021

a) \(\Rightarrow9x^2+24x+16-9x^2+1=49\)

\(\Rightarrow24x=32\Rightarrow x=\dfrac{4}{3}\)

b) \(\Rightarrow x^2-13x+22=0\)

\(\Rightarrow\left(x-11\right)\left(x-2\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=11\\x=2\end{matrix}\right.\)

c) \(\Rightarrow x^2-3x-10=0\)

\(\Rightarrow\left(x-5\right)\left(x+2\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=5\\x=-2\end{matrix}\right.\)

30 tháng 9 2021

\(A=6x^2+23x+21-\left(6x^2+23x-55\right)=76\\ B=x^4+x^3-x^2-2x^2-2x+2-x^4-x^3+3x^2+2x\\ =2\\ C=x^4+x^3-3x^2-2x-\left(x^4+x^3-x^2-2x^2-2x+2\right)\\ =-2\)

19 tháng 9 2023

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20 tháng 9 2023

chữ đẹp v :) 

23 tháng 11 2016

dài thế ai trả lời đc hả ?

23 tháng 11 2016

tu lam di luoi vua thoi

11 tháng 1 2022

\(a.\left(3x+2\right)\left(x^2-1\right)=\left(9x^2-4\right)\left(x+1\right)\)

\(\Leftrightarrow\left(3x+2\right)\left(x+1\right)\left(x-1\right)=\left(3x-2\right)\left(3x+2\right)\left(x+1\right)\)

\(\Leftrightarrow x-1=3x-2\)

\(\Leftrightarrow2x=1\)

\(\Leftrightarrow x=\dfrac{1}{2}\)

c: =>x-3=0

hay x=3

d: \(\Leftrightarrow\left(3x-1\right)\cdot\left(x^2+2-7x+10\right)=0\)

\(\Leftrightarrow\left(3x-1\right)\left(x-3\right)\left(x-4\right)=0\)

hay \(x\in\left\{\dfrac{1}{3};3;4\right\}\)