Giúp mình vs.

\(\left|x-1\right|=2x-1\)

\(\Rightarrow\orbr{\begin{cases}x-1=2x-1\\x-1=-2x+1\end{cases}\left(đk:2x\ge\frac{1}{2}\right)}\)

\(\Rightarrow\orbr{\begin{cases}x=0\left(ktm\right)\\x=\frac{2}{3}\left(tm\right)\end{cases}}\)

vậy \(x=\frac{2}{3}\)

nhìu dữ

a)3/2

b)-1/3

c)-5/6

d)0

e)-1/2

Bài 2

a=3

b=1/2

c=-1/3

d=0

e=9

f=-2/3

mk ko làm rõ đâu  nhe

Bạn chú ý đăng lẻ câu hỏi! 1/

a/ \(=x^3-2x^5\)

b/\(=5x^2+5-x^3-x\)

c/ \(=x^3+3x^2-4x-2x^2-6x+8=x^3=x^2-10x+8\)

d/ \(=x^2-x^3+4x-2x+2x^2-8=3x^2-x^3+2x-8\)

e/ \(=x^4-x^2+2x^3-2x\)

f/ \(=\left(6x^2+x-2\right)\left(3-x\right)=17x^2+5x-6-6x^3\)

a) (x - 2)² - (x - 3)(x + 3) = 17

⇔ (x² - 4x + 4) - (x² - 9) = 17

⇔ x² - 4x + 4 - x² + 9 = 17

⇔ 13 - 4x = 17

⇔ - 4x = -4

⇔ x = 1

b) 4(x - 3)² - (2x - 1)(2x + 1) = 10

⇔ [2(x - 3)]² - (4x² - 1) = 10

⇔ (2x - 6)² - 4x² + 1 = 10

⇔ 4x² - 24x + 36 - 4x² + 1 = 10

⇔ - 24x = -27

⇔ x = \(\dfrac{9}{8}\)

c) (x - 4)² - (x - 2)(x + 2) = 36

⇔ x² - 8x + 16 - x² + 4 = 36

⇔ -8x = 16

⇔ x = -2

d) (2x + 3)² - (2x - 1)(2x + 1) = 10

⇔ 4x² + 12x + 9 - 4x² + 1 = 10

⇔ 12x = 0

⇔ x = 0

Tìm x ,biết :

a, \(\left(x-2\right)^2-\left(x-3\right)\left(x+3\right)=17\)

\(\Rightarrow x^2-4x+4-x^2+9=17\)

\(\Rightarrow-4x+13=17\)

\(\Rightarrow-4x=4\)

\(\Rightarrow x=-1\)

b,\(4\left(x-3\right)^2-\left(2x-1\right)\left(2x+1\right)=10\)

\(\Rightarrow4\left(x^2-6x+9\right)-4x^2+1=10\)

\(\Rightarrow4x^2-24x+36-4x^2+1=10\)

⇒ \(-24x+37=10\)

\(\Rightarrow-24x=-27\)

\(\Rightarrow x=\dfrac{-27}{-24}=\dfrac{9}{8}\)

c,\(\left(x-4\right)^2-\left(x-2\right)\left(x+2\right)=36\)

⇒ \(x^2-8x+16-x^2+4=36\)

⇒ \(-8x+20=36\)

⇒ \(-8x=16\Rightarrow x=-2\)

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

\(\Rightarrow4x^2+12x+9-4x^2+1=10\)

\(\Rightarrow12x+10=10\)

\(\Rightarrow12x=0\Rightarrow x=0\)

a.

\(\left(x-2\right)^2-\left(x-3\right)\left(x+3\right)=17\\ \Leftrightarrow\left(x^2-4x+4\right)-\left(x^2-9\right)=17\\ \Leftrightarrow-4x+13=17\\ \Leftrightarrow x=-1\)

b.

\(4\left(x-3\right)^2-\left(2x-1\right)\left(2x+1\right)=10\\ \Leftrightarrow4\left(x^2-6x+9\right)-\left(4x^2-1\right)=10\\ \Leftrightarrow\left(4x^2-24x+36\right)-\left(4x^2-1\right)=10\\ \Leftrightarrow-24x+37=10\\ \Leftrightarrow x=\dfrac{9}{8}\)

c.

\(\left(x-4\right)^2-\left(x-2\right)\left(x+2\right)=36\\ \Leftrightarrow\left(x^2-8x+16\right)-\left(x^2-4\right)=36\\ \Leftrightarrow-8x+20=36\\ \Leftrightarrow x=-2\)

d.

\(\left(2x+3\right)^2-\left(2x-1\right)\left(2x+1\right)=10\\ \Leftrightarrow\left(4x^2+12x+9\right)-\left(4x^2-1\right)=10\\ \Leftrightarrow12x+10=10\\ \Leftrightarrow x=0\)

1: =>3^x=81

=>x=4

2: =>2^x=8

=>x=3

3: =>x^3=2^3

=>x=2

4: =>x^20-x=0

=>x(x^19-1)=0

=>x=0 hoặc x=1

5: =>2^x=32

=>x=5

6: =>(2x+1)^3=9^3

=>2x+1=9

=>2x=8

=>x=4

7: =>x^3=115

=>\(x=\sqrt[3]{115}\)

8: =>(2x-15)^5-(2x-15)^3=0

=>(2x-15)^3*[(2x-15)^2-1]=0

=>2x-15=0 hoặc (2x-15)^2-1=0

=>2x-15=0 hoặc 2x-15=1 hoặc 2x-15=-1

=>x=15/2 hoặc x=8 hoặc x=7

1. Tìm số tự nhiên x biết:

1) \(3^x.3=243\)

\(3^x=243:3\)

\(3^x=81\)

\(3^x=3^4\)

\(\Rightarrow x=4\)

_____

2) \(7.2^x=56\)

\(2^x=56:7\)

\(2^x=8\)

\(2^x=2^3\)

\(\Rightarrow x=3\)

_____

3) \(x^3=8\)

\(x^3=2^3\)

\(\Rightarrow x=3\)

_____

4) \(x^{20}=x\)

\(x^{20}-x=0\)

\(x\left(x^{19}-1\right)=0\)

\(\Rightarrow x=0\) hoặc \(x=1\)

5) \(2^x-15=17\)

\(2^x=17+15\)

\(2^x=32\)

\(2^x=2^5\)

\(\Rightarrow x=5\)

_____

6) \(\left(2x+1\right)^3=9.81\)

\(\left(2x+1\right)^3=729=9^3\)

\(\rightarrow2x+1=9\)

\(2x=9-1\)

\(2x=8\)

\(x=8:2\)

\(\Rightarrow x=4\)

_____

7) \(x^6:x^3=125\)

\(x^3=125\)

\(x^3=5^3\)

\(\Rightarrow x=5\)

_____

8) \(\left(2x-15\right)^5=\left(2x-15\right)^3\)

\(\rightarrow\left(2x-15\right)^5-\left(2x-15\right)^3=0\)

\(\left(2x-15\right)^3.\left[\left(2x-15\right)^2-1\right]=0\)

\(\Leftrightarrow\left\{{}\begin{matrix}\left(2x-15\right)^3=0\\\left(2x-15\right)^2-1=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{15}{2}\\x=7\\x=8\end{matrix}\right.\)

_____

9) \(3^{x+2}-5.3^x=36\)

\(3^x.\left(3^2-5\right)=36\)

\(3^x.\left(9-5\right)=36\)

\(3^x.4=36\)

\(3^x=36:4\)

\(3^x=9\)

\(3^x=3^2\)

\(\Rightarrow x=2\)

_____

10) \(7.4^{x-1}+4^{x+1}=23\)

\(\rightarrow7.4^{x-1}+4^{x-1}.4^2=23\)

\(4^{x-1}.\left(7+4^2\right)=23\)

\(4^{x-1}.\left(7+16\right)=23\)

\(4^{x-1}.23=23\)

\(4^{x-1}=23:23\)

\(4^{x-1}=1\)

\(4^{x-1}=4^1\)

\(\rightarrow x-1=0\)

\(x=0+1\)

\(\Rightarrow x=1\)

Chúc bạn học tốt

Bài 1

A= (x-2)(2x-1)-2x(x+3)=2x²-x-4x+2-2x²-6x=-11x+2

Bài 1:

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

\(A=2x^2-x-4x+2-2x^2-6x\)

\(A=-11x+2\)

b) \(B=\left(3x-2\right)\left(2x+1\right)-\left(6x-1\right)\left(x+2\right)\)

\(B=6x^2+3x-4x-2-6x^2-12x+x+2\)

\(B=-12x\)

c) \(C=6x\left(2x+3\right)-\left(4x-1\right)\left(3x-2\right)\)

\(C=12x^2+18x-12x^2+8x+3x-2\)

\(C=29x-2\)

d) \(D=\left(2x+3\right)\left(5x-2\right)+\left(x+4\right)\left(2x-1\right)-6x\left(2x-3\right)\)

\(D=10x^2-4x+15x-6+2x^2-x+8x-4-12x^2+18x\)

\(D=36x-10\)

Bài 2: 

a: Ta có: \(2x\left(3x-5\right)\left(x+11\right)-3x\left(2x+3\right)\left(x+7\right)\)

\(=2x\left(3x^2+33x-5x-55\right)-3x\left(2x^2+14x+3x+21\right)\)

\(=6x^3+56x^2-110x-6x^2-51x^2-63x\)

\(=-117x\)

b: Ta có: \(\left(x^2+5x-6\right)\left(x-1\right)-\left(x+2\right)\left(x^2-x+1\right)-x\left(3x-10\right)\)

\(=x^3+4x^2-11x+6-\left(x^3-x^2+x+2x^2-2x+2\right)-3x^2+10x\)

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

=4

c: Ta có: \(\left(x^2+x+1\right)\left(x-1\right)-x^2\left(x+1\right)+x^2-5\)

\(=x^3-1-x^3-x^2+x^2-5\)

=-6

phân tích các số sau ra thừa số nguyên tố 48;56;84;105;360