\(\dfrac{2+x}{5}-0,5x=\dfrac{1-2x}{4}+0,25\)

\(\Leftrightarrow\dfrac{2+x}{5}-\dfrac{x}{2}=\dfrac{1-2x}{4}+\dfrac{1}{4}\)

\(\Leftrightarrow\dfrac{2+x}{5}-\dfrac{x}{2}=\dfrac{1-2x+1}{4}\)

\(\Leftrightarrow\dfrac{2+x}{5}-\dfrac{x}{2}=\dfrac{2-2x}{4}\)

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

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

\(\Leftrightarrow\dfrac{2+x}{5}=\dfrac{1}{2}\)

\(\Leftrightarrow2\left(2+x\right)=5\\ \Leftrightarrow2x+4-5=0\\ \Leftrightarrow2x-1=0\\ \Leftrightarrow x=\dfrac{1}{2}\)

\(PT.\Rightarrow\) \(\dfrac{8+4x-10x-5+10x-5}{20}=0.\Rightarrow4x=2.\Leftrightarrow x=\dfrac{1}{2}.\)

\(\dfrac{2+x}{5}-0,5x=\dfrac{1-2x}{4}+0,25\\ \Leftrightarrow\dfrac{4.\left(2+x\right)}{20}-\dfrac{20.0,5x}{20}=\dfrac{5.\left(1-2x\right)}{20}+\dfrac{0,25.20}{20}\\ \Leftrightarrow8+4x-10x=5-10x+5\\ \Leftrightarrow4x=2\\ \Leftrightarrow x=\dfrac{1}{2}\\ \Rightarrow S=\left\{\dfrac{1}{2}\right\}\)

=>0,2x+0,4-0,5x=0,25-0,5x+0,25

=>0,2x+0,4=0,5

=>0,2x=0,1

=>x=1/2

a) \(\dfrac{x}{3}-\dfrac{2x+1}{2}=\dfrac{x}{6}-x\)

\(\Leftrightarrow\dfrac{2x}{6}-\dfrac{3\left(2x+1\right)}{6}=\dfrac{x}{6}=\dfrac{6x}{6}\)

\(\Leftrightarrow2x-3\left(2x+1\right)=x-6x\)

\(\Leftrightarrow2x-6x-3=x-6x\)

\(\Leftrightarrow2x-6x-x+6x=3\)

\(\Leftrightarrow x=3\)

\(S=\left\{3\right\}\)

b) \(\dfrac{2+x}{5}-0,5x=\dfrac{1-2x}{4}+0,25\)

\(\Leftrightarrow\dfrac{4\left(2+x\right)}{20}-\dfrac{10x}{20}=\dfrac{5\left(1-2x\right)}{20}+\dfrac{5}{20}\)

\(\Leftrightarrow4\left(2+x\right)-10x=5\left(1-2x\right)+5\)

\(\Leftrightarrow8+4x-10x=5-10x+5\)

\(\Leftrightarrow4x-10x+10x=5+5-8\)

\(\Leftrightarrow4x=2\)

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

\(S=\left\{\dfrac{1}{2}\right\}\)

a)X= 3

b)X= 0,5

giải pt sau

g) 11+8x-3=5x-3+x

\(\Leftrightarrow\) 8x + 8 = 6x - 3

<=> 8x-6x = -3 - 8

<=> 2x = -11

=> x=-\(\dfrac{11}{2}\)

Vậy tập nghiệm của PT là : S={\(-\dfrac{11}{2}\)}

h)4-2x+15=9x+4-2x

<=> 19 - 2x = 7x + 4

<=> -2x - 7x = 4 - 19

<=> -9x = -15

=> x=\(\dfrac{15}{9}=\dfrac{5}{3}\)

Vậy tập nghiệm của pt là : S={\(\dfrac{5}{3}\)}

g)\(\dfrac{3x+2}{2}-\dfrac{3x+1}{6}=\dfrac{5}{3}+2x\)

<=> \(\dfrac{3\left(3x+2\right)}{6}-\dfrac{3x+1}{6}=\dfrac{5.2+6.2x}{6}\)

<=> 9x + 6 - 3x + 1 = 10 + 12x

<=> 6x + 7 = 10 + 12x

<=> 6x -12x = 10-7

<=> -6x = 3

=> x= \(-\dfrac{1}{2}\)

Vậy tập nghiệm của PT là : S={\(-\dfrac{1}{2}\)}

\(h,\dfrac{x+4}{5}-x+4=\dfrac{4x+2}{5}-5\)

<=> \(\dfrac{x+4-5\left(x+4\right)}{5}=\dfrac{4x+2-5.5}{5}\)

<=> x + 4 - 5x - 20 = 4x + 2 - 25

<=> x - 5x - 4x = 2-25-4+20

<=> -8x = -7

=> x= \(\dfrac{7}{8}\)

Vậy tập nghiệm của PT là S={\(\dfrac{7}{8}\)}

\(i,\dfrac{4x+3}{5}-\dfrac{6x-2}{7}=\dfrac{5x+4}{3}+3\)

<=> \(\dfrac{21\left(4x+3\right)}{105}\)-\(\dfrac{15\left(6x-2\right)}{105}\)=\(\dfrac{35\left(5x+4\right)+3.105}{105}\)

<=> 84x + 63 - 90x + 30 = 175x + 140 + 315

<=> 84x - 90x - 175x = 140 + 315 - 63 - 30

<=> -181x = 362

=> x = -2

Vậy tập nghiệm của PT là : S={-2}

K) \(\dfrac{5x+2}{6}-\dfrac{8x-1}{3}=\dfrac{4x+2}{5}-5\)

<=> \(\dfrac{5\left(5x+2\right)}{30}-\dfrac{10\left(8x-1\right)}{30}=\dfrac{6\left(4x+2\right)-150}{30}\)

<=> 25x + 10 - 80x - 10 = 24x + 12 - 150

<=> -55x = 24x - 138

<=> -55x - 24x = -138

=> -79x = -138

=> x=\(\dfrac{138}{79}\)

Vậy tập nghiệm của PT là S={\(\dfrac{138}{79}\)}

m) \(\dfrac{2x-1}{5}-\dfrac{x-2}{3}=\dfrac{x+7}{15}\)

<=> \(\dfrac{3\left(2x-1\right)-5\left(x-2\right)}{15}=\dfrac{x+7}{15}\)

<=> 6x - 3 - 5x + 10 = x+7

<=> x + 7 = x+7

<=> 0x = 0

=> PT vô nghiệm

Vậy S=\(\varnothing\)

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

<=> \(\dfrac{1}{4}x+\dfrac{3}{4}=3-\dfrac{1}{2}x-\dfrac{1}{2}-\dfrac{1}{3}x-\dfrac{2}{3}\)

<=> \(\dfrac{1}{4}x+\dfrac{1}{2}x+\dfrac{1}{3}x=3-\dfrac{1}{2}-\dfrac{2}{3}-\dfrac{3}{4}\)

<=> \(\dfrac{13}{12}x=\dfrac{13}{12}\)

=> x= 1

Vậy S={1}

p) \(\dfrac{x}{3}-\dfrac{2x+1}{6}=\dfrac{x}{6}-6\)

<=> \(\dfrac{2x-2x+1}{6}=\dfrac{x-36}{6}\)

<=> 2x -2x + 1= x-36

<=> 2x-2x-x = -37

=> x = 37

Vậy S={37}

q) \(\dfrac{2+x}{5}-0,5x=\dfrac{1-2x}{4}+0,25\)

<=> \(\dfrac{4\left(2+x\right)-20.0,5x}{20}=\dfrac{5\left(1-2x\right)+20.0,25}{20}\)

<=> 8 + 4x - 10x = 5 - 10x + 5

<=> 4x-10x + 10x = 5+5-8

<=> 4x = 2

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

Vậy S={\(\dfrac{1}{2}\)}

g) \(11+8x-3=5x-3+x\)

\(\Leftrightarrow8+8x=6x-3\)

\(\Leftrightarrow8x-6x=-3-8\)

\(\Leftrightarrow2x=-11\)

\(\Leftrightarrow x=-\dfrac{11}{2}\)

h, \(4-2x+15=9x+4-2x\)

\(\Leftrightarrow-2x-9x+2x=4-4-15\)

\(\Leftrightarrow-9x=-15\)

\(\Leftrightarrow x=\dfrac{-15}{-9}=\dfrac{5}{3}\)

g) 11+8x-3=5x-3+x

=> 8x -5x -x = -3 -11+3

<=> 2x = -11

<=> x = \(\dfrac{-11}{2}\)

h)4-2x+15=9x+4-2x

=> -2x -9x +2x = 4-4-15

<=> -9x = -15

<=> x = \(\dfrac{5}{3}\)

Tìm x:

a, x+30%=-1,3

<=> x+0,3=-1,3

<=> x=-1,3-0,3

<=> x=-1,6

Vậy x=-1,6

b, 0,5x-\(\dfrac{2}{3}x\) =\(\dfrac{7}{12}\)

<=>\(\dfrac{-1}{6}x\)=\(\dfrac{7}{12}\)

<=> x=\(\dfrac{-7}{2}\)

Vậy x=\(\dfrac{-7}{2}\)

a, \(\dfrac{3}{4}x=-\dfrac{9}{8}\)
x= \(-\dfrac{3}{2}\)
b, |x| + 0,25= 5,25
|x | = 5
=> x\(\in\){ +- 5}
Ko chắc đúng, kiểm tra trc khi làm

\(\dfrac{2x-1}{3}=\dfrac{-5}{0.6}\)

\(\Leftrightarrow2x-1=-25\)

hay x=-12

1: \(\Leftrightarrow\left(x+1\right)^2=4\)

=>x+1=2 hoặc x+1=-2

=>x=1 hoặc x=-3

2: \(\Leftrightarrow7x-21=5x+25\)

=>2x=46

=>x=23

3: \(\Leftrightarrow x^2+4x+3=x^2+0.5x+4x+2\)

=>4,5x+2=4x+3

=>x=1

\(a,\dfrac{-3}{4}x+1=\dfrac{5}{6}\\ \Rightarrow\dfrac{-3}{4}x=\dfrac{-1}{6}\\ \Rightarrow x=\dfrac{2}{9}\\ b,\left(2x-3\right)\left(x-5\right)=0\\ \Rightarrow\left[{}\begin{matrix}2x-3=0\\x-5=0\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=\dfrac{3}{2}\\x=5\end{matrix}\right.\\ c,\dfrac{1}{2}-\left|x+1\right|=0,25\\ \Rightarrow\left|x+1\right|=0,25\\ \Rightarrow\left[{}\begin{matrix}x+1=0,25\\x+1=-0,25\end{matrix}\right.\\ \Rightarrow\left[{}\begin{matrix}x=-0,75\\x=-1,25\end{matrix}\right.\)

a: =>-3/4x=-1/6

hay x=2/9

b: =>2x-3=0 hoặc x-5=0

hay x=3/2 hoặc x=5

c: =>|x+1|=1/4

\(\Leftrightarrow x+1\in\left\{\dfrac{1}{4};-\dfrac{1}{4}\right\}\)

hay \(x\in\left\{-\dfrac{3}{4};-\dfrac{5}{4}\right\}\)

b, \(=>2x-3=0\)      hay       \(x-5=0\)

           \(2x=0+3\)                   \(x=0+5\)

          \(2x=3\)                           \(x=5\)

            \(x=\dfrac{3}{2}\)

Vậy x ϵ { \(\dfrac{3}{2}\);5}

a: =>3/2x=64/15

=>x=128/45

b: =>-1/6x=7/12

=>x=-7/2

c: =>11/2*x=1/2

=>x=1/2:11/2=1/11