K
Khách

Hãy nhập câu hỏi của bạn vào đây, nếu là tài khoản VIP, bạn sẽ được ưu tiên trả lời.

12 tháng 5 2016

a/ (3x - 1).(1/2.5) = 0 => 3x - 1 = 0 => 3x = 1 => x = 1/3

b/ 1/4 + 1/3 : (2x - 1) = 5 => 1/3 : (2x - 1) = 19/4 => 2x - 1 = 4/57 => 2x = 61/57 => x = 61/114

c/ (2x + 2/5)2 - 9/25 = 0 => (2x + 2/5)2 = 9/25 => 2x + 2/5 = 3/5 => 2x = 1/5 => x = 1/10 

                                                         hoặc             2x + 2/5 = -3/5 => 2x = -1 => x = -1/2

     Vậy x = {1/10 ; -1/2}

d/ (3x - 1/2)3 + 1/9 = 0 => (3x - 1/2)3 = -1/9 => 3x - 1/2 = -1/3 => 3x = 1/6 => x = 1/18

12 tháng 5 2016

bạn viết rõ hơn được không

10 tháng 5 2016

câu1

(3x-1).(1/2x5)=0

=>3x-1=0               hoặc  1/2x5=0

=>x=1/3                            =>x=0

câu2

1/4+1/3 :(2x-1)=5

=> 1/3:(2x-1)=19/4

=>2x-1       =57/4

=>2x=61/4

=>x=61/8

còn hai câu sau bn ghi đề mik ko hỉu

10 tháng 5 2016

1.

a)(3x-1)(1/2x5)=0

=>3x-1=0 hoặc 1/2x5=0

3x=0+1               x=0:1/2:5

x=1/3                  x=0

Vậy x=1/3 hoặc x=0

b)1/4+1/3:(2x-1)=5

1/3:(2x-1)=5-1/4=20/4-1/4=19/4

2x-1=1/3:19/4=1/3*4/19=4/57

2x=4/57+1=4/57+57/57=61/57

x=61/57:2=61/57*1/2=61/114

Vậy x=61/114

c)(2x+2/5)2-9/25=0=02-9/25

=>2x+2/5=0

2x=0-2/5

x=-2/5:2=-2/5*1/2

x=-1/5

Vậy x=-1/5

d)(3x-1/2)3+1/9=0=03+1/9

=>3x-1/2=0

3x=0+1/2

x=1/2:3=1/2*1/3

x=1/6

Vậy x=1/6

16 tháng 4 2022

a) \(x=\dfrac{25}{72}\)

b)\(x=-\dfrac{1}{4}\)

  \(x=\dfrac{3}{2}\)

c)\(x=\dfrac{5}{4}\) hoặc

  x \(=\dfrac{8}{5}\)

d và e chịu vì mk kg giỏi lắm về mũ 

f)\(x=-2\)

G)\(x=-\dfrac{5}{12}\)

24 tháng 6 2016

c)\(\left(2x+\frac{3}{5}\right)^2-\frac{9}{25}=0\)

\(\Rightarrow\left(2x+\frac{3}{5}\right)^2=\frac{9}{25}\)

\(\Rightarrow2x+\frac{3}{5}=\pm\frac{3}{5}\)

  • Với \(2x+\frac{3}{5}=\frac{3}{5}\)

\(\Rightarrow2x=0\Rightarrow x=0\)

  • Với \(2x+\frac{3}{5}=-\frac{3}{5}\)

\(\Rightarrow2x=-\frac{6}{5}\Rightarrow x=-\frac{3}{5}\)

24 tháng 6 2016

a)x=10

b)x=61/114

c)x=0

d)sai cái gì đó

Đáp án là gì nhưng lời giải ???????

2 tháng 6 2017
  1. ĐK \(x\ne0\Rightarrow\)\(\left(3x-1\right)\left(5-\frac{1}{2x}\right)=0\Leftrightarrow\orbr{\begin{cases}3x-1=0\\5-\frac{1}{2x}=0\end{cases}\Leftrightarrow\orbr{\begin{cases}3x=1\\10x=1\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=\frac{1}{3}\\x=\frac{1}{10}\end{cases}}}\)
  2. ĐK \(2x-1\ne0\Leftrightarrow x\ne\frac{1}{2}\)\(\frac{1}{4}+\frac{1}{3}:\left(2x-2\right)=5\Leftrightarrow\frac{1}{4}+\frac{1}{3\left(2x-1\right)}=5\)\(\Leftrightarrow3\left(2x-1\right)+4=4.3.5.\left(2x-1\right)\Leftrightarrow6x-3+4=120x-60\)\(\Leftrightarrow114x=61\Leftrightarrow x=\frac{61}{114}\)
  3. \(\left(2x+\frac{3}{5}\right)^2-\left(\frac{3}{5}\right)^2=0\Leftrightarrow\left(2x+\frac{3}{5}-\frac{3}{5}\right)\left(2x+\frac{3}{5}+\frac{3}{5}\right)=0\)\(2x\left(2x+\frac{6}{5}\right)=0\Leftrightarrow\orbr{\begin{cases}x=0\\2x=-\frac{6}{5}\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=0\\x=-\frac{3}{5}\end{cases}}\)
  4. \(3\left(3x-\frac{1}{2}\right)^3+\frac{1}{9}=0\Leftrightarrow3\left(3x-\frac{1}{2}\right)^3=-\frac{1}{9}\)\(\Leftrightarrow\left(3x-\frac{1}{2}\right)^3=-\frac{1}{27}\Leftrightarrow3x-\frac{1}{2}=\sqrt[3]{-\frac{1}{27}}\)\(\Leftrightarrow3x-\frac{1}{2}=-\frac{1}{3}\Leftrightarrow3x=\frac{1}{6}\Leftrightarrow x=\frac{1}{18}\)
3 tháng 8 2018

b, x = -5/3 hoặc x = 4/3.

c, x = 0 hoặc x = 3, -3.

d, x = 0 hoặc x = 2, -2.

e, x = 1 hoặc x = \(\dfrac{-1}{2}\).

a: \(\Leftrightarrow x^2-40x+400-x^2-4x-3=-7\)

=>-44x+397=-7

=>-44x=-404

hay x=101

b: \(\Leftrightarrow\left[{}\begin{matrix}3x+5=0\\4-3x=0\end{matrix}\right.\Leftrightarrow x\in\left\{-\dfrac{5}{3};\dfrac{4}{3}\right\}\)

c: \(\Leftrightarrow x\left(x^2-9\right)=0\)

=>x(x-3)(x+3)=0

hay \(x\in\left\{0;3;-3\right\}\)

d: \(\Leftrightarrow x\left(x-2\right)\left(x+2\right)=0\)

hay \(x\in\left\{0;2;-2\right\}\)

e: =>(2x+1)(1-x)=0

=>x=-1/2 hoặc x=1

1 tháng 6 2018

Tìm x:

1. \(25x^2-20x+4=0\)

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

\(5x-2=0\)

\(5x=2\)

\(x=\dfrac{2}{5}\)

⇒ S = \(\left\{\dfrac{2}{5}\right\}\)

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

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

\(4x^2-12x+9-4x^2+1=0\)

\(-12x+10=0\)

\(-12x=-10\)

\(x=\dfrac{5}{6}\)

⇒ S \(=\left\{\dfrac{5}{6}\right\}\)

3. \(\left(\dfrac{1}{2}x-1\right)\left(\dfrac{1}{2}x+1\right)-\left(\dfrac{1}{2}x-1\right)^2=0\)

\(\dfrac{1}{4}x^2-1-\left(\dfrac{1}{4}x^2-x+1\right)=0\)

\(\dfrac{1}{4}x^2-1-\dfrac{1}{4}x^2+x-1=0\)

\(-2+x=0\)

\(x=2\)

⇒ S \(=\left\{2\right\}\)

4. \(\left(2x-3\right)^2+\left(2x+5\right)^2=8\left(x+1\right)^2\)

\(4x^2-12x+9+4x^2+20x+25=8\left(x^2+2x+1\right)\)

\(8x^2+8x+34=8x^2+16x+8\)

\(8x+34=16x+8\)

\(8x-16x=8-34\)

\(-8x=-26\)

\(x=\dfrac{13}{4}\)

⇒ S \(=\left\{\dfrac{13}{4}\right\}\)

5.\(4x^2+12x-7=0\)

\(4x^2+14x-2x-7=0\)

\(2x\left(2x+7\right)-\left(2x+7\right)=0\)

\(\left(2x+7\right)\left(2x-1\right)=0\)

\(\left[{}\begin{matrix}2x+7=0\\2x-1=0\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=\dfrac{-7}{2}\\x=\dfrac{1}{2}\end{matrix}\right.\)

⇒ S \(=\left\{\dfrac{-7}{2};\dfrac{1}{2}\right\}\)

6. \(\dfrac{1}{4}x^2+\dfrac{2}{3}x-\dfrac{5}{9}=0\)

\(9x^2+24x-20=0\)

\(9x^2+30x-6x-20=0\)

\(3x\left(3x+10\right)-2\left(3x+10\right)=0\)

\(\left(3x+10\right)\left(3x-2\right)=0\)

\(\left[{}\begin{matrix}3x+10=0\\3x-2=0\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=\dfrac{-10}{3}\\x=\dfrac{2}{3}\end{matrix}\right.\)

⇒ S \(=\left\{\dfrac{-10}{3};\dfrac{2}{3}\right\}\)

1 tháng 6 2018

7. \(24\dfrac{8}{9}-\dfrac{1}{4}x^2-\dfrac{1}{3}x=0\)

\(\dfrac{224}{9}-\dfrac{1}{4}x^2-\dfrac{1}{3}x=0\)

\(896-9x^2-12x=0\)

\(-896+9x^2+12x=0\)

\(9x^2+12x-896=0\)

\(9x^2-84x+96x-896=0\)

\(3x\left(3x-28\right)+32\left(3x-28\right)=0\)

\(\left(3x-28\right)\left(3x+32\right)=0\)

\(\left[{}\begin{matrix}3x-28=0\\3x+32=0\end{matrix}\right.\)

\(\left[{}\begin{matrix}x=\dfrac{28}{3}\\x=\dfrac{-32}{3}\end{matrix}\right.\)

⇒ S \(=\left\{\dfrac{-32}{3};\dfrac{28}{3}\right\}\)

11 tháng 5 2016

a) 

Để \(\left(3x-1\right).\left(-\frac{1}{2}x+5\right)=0\)=> 3x-1=0 hoặc \(-\frac{1}{2}x+5=0\)

=> x= \(\frac{1}{3}\) hoăc \(x=10\)

b)

\(\frac{1}{4}+\frac{1}{3}:\left(2x-1\right)=5\) => \(\frac{1}{3}:\left(2x-1\right)=5-\frac{1}{4}=\frac{19}{4}=>2x-1=\frac{1}{3}:\frac{19}{4}=\frac{4}{57}=>x=\frac{61}{114}\)

c) \(\left(2x+\frac{3}{5}\right)^2-\frac{9}{25}=0=>\left(2x+\frac{3}{5}\right)^2=\frac{9}{25}\)\(=>2x+\frac{3}{5}\in\left\{\pm\frac{3}{5}\right\}=>2x\in\left\{0;\frac{-6}{5}\right\}=>x\in\left\{0;\frac{-3}{5}\right\}\)

d) Xem lại đề

 

28 tháng 7 2017

a) để (3x-1).(\(-\dfrac{1}{2}x+5\))=0

=> 3x-1 hoặc \(-\dfrac{1}{2}x+5\) =0

TH1 : 3x-1=0

3x = 0+1=1

x = 1:3 = \(\dfrac{1}{3}\)

TH2 : \(-\dfrac{1}{2}x+5\)= 0

\(-\dfrac{1}{2}x\)= 0 -5 = -5

x= -5 : \(-\dfrac{1}{2}\)

x= 10

b) (5/2-3x)=25/9

            3x = 5/2-25/9

            3x =-5/18

              x =-5/18:3

              x=-5/54

\(e.\left(x-1\right)^5=-32\)

  \(\left(x-1\right)^5=\left(-2\right)^5\)

   \(x-1=-2\)

   \(x\)      \(=-2+1\)

   \(x\)        \(=-1\)

Vậy \(x=-1\)