1) \(|5x-3|=|7-x|\)

\(\Leftrightarrow\orbr{\begin{cases}5x-3=7-x\\5x-3=x-7\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}6x=10\\4x=-4\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=\frac{5}{3}\\x=-1\end{cases}}\)

Vậy...

2) \(2.|3x-1|-3x=7\)

\(\Leftrightarrow2.|3x-1|=7+3x\)

\(\Leftrightarrow\orbr{\begin{cases}2.\left(3x-1\right)=7+3x\\2.\left(3x-1\right)=-7-3x\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}6x-2=7+3x\\6x-2=-7-3x\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}3x=9\\9x=-5\end{cases}}\)

\(\Leftrightarrow\orbr{\begin{cases}x=3\\x=\frac{-5}{9}\end{cases}}\)

Vậy...

5) \(\text{1,6 - |x + 1,5| = 0}\)

\(|x + 1,5| = 1,6-0\)

\(\text{|x + 1,5| = 1,6}\)

\( |x | = 1,6-1,5\)

\(|x|=0,1\)

a: =>-2x=-8

hay x=4

b: =>7x=-21

hay x=-3

c: =>0,25x=-1,5

hay x=-6

d: =>5,3x=6,36

hay x=6/5

e: =>-4x=-12

hay x=3

f: =>-10x=-10

hay x=1

g: =>2x+2-3-2x=0

=>-1=0(vô lý)

h: =>3-3x+4x-3=0

=>x=0

a,

\(3-x=x-5\\ \Leftrightarrow3x-x+5=0\Leftrightarrow2x+5=0\)

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

b, \(\Rightarrow x=-\dfrac{21}{7}=-3\)

c, \(\Leftrightarrow x=\left(0-1,5\right):0,25=-6\)

a. <=> 2x=8 hay x=4

b.<=> x= -21/7 = -3

c. <=> x= -1,5/ 0,25=-6

d. <=> x= -6,36/-5,3=1,2

e.<=> 4x=12 hay x= 3

f. <=> 10x = 10 hay x = 1

g. <=> 2x +2 = 3 + 2x

<=> 2=3 ( vô lí )

h.<=> 3 - 3x + 4x -3 =0

<=> x=0

Bài 1:

a) Ta có: 7x+12=0

\(\Leftrightarrow7x=-12\)

hay \(x=-\frac{12}{7}\)

Vậy: \(x=-\frac{12}{7}\)

b) Ta có: 5x-2=0

\(\Leftrightarrow5x=2\)

hay \(x=\frac{2}{5}\)

Vậy: \(x=\frac{2}{5}\)

c) Ta có: 12-6x=0

\(\Leftrightarrow6x=12\)

hay x=2

Vậy: x=2

d) Ta có: -2x+14=0

⇔-2x=-14

hay x=7

Vậy: x=7

Bài 2:

a) Ta có: 3x+1=7x-11

⇔3x+1-7x+11=0

⇔-4x+12=0

⇔-4x=-12

hay x=3

Vậy: x=3

b) Ta có: 2x+x+12=0

⇔3x+12=0

⇔3x=-12

hay x=-4

Vậy: x=-4

c) Ta có: x-5=3-x

⇔x-5-3+x=0

⇔2x-8=0

⇔2x=8

hay x=4

Vậy: x=4

d) Ta có: 7-3x=9-x

⇔7-3x-9+x=0

⇔-2x-2=0

⇔-2x=2

hay x=-1

Vậy: x=-1

e) Ta có: 5-3x=6x+7

⇔5-3x-6x-7=0

⇔-9x-2=0

⇔-9x=2

hay \(x=\frac{-2}{9}\)

Vậy: \(x=\frac{-2}{9}\)

f) Ta có: 11-2x=x-1

⇔11-2x-x+1=0

⇔12-3x=0

⇔3x=12

hay x=4

Vậy: x=4

g) Ta có: 15-8x=9-5

⇔15-8x=4

⇔8x=11

hay \(x=\frac{11}{8}\)

Vậy: \(x=\frac{11}{8}\)

Bài 3:

a) Ta có: 0,25x+1,5=0

⇔0,25x=-1,5

hay x=-6

Vậy: x=-6

b) Ta có: 6,36-5,2x=0

⇔5,2x=6,36

hay \(x=\frac{159}{130}\)

Vậy: \(x=\frac{159}{130}\)

1. 3y = 0

=> y = 0

2. 1+x = 0

<+ x = -1

3.

\(1-2t=0\)

\(\Leftrightarrow2t=1\)

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

4. 2x +x + 3 =0

\(\Leftrightarrow3x+3=0\)

\(\Leftrightarrow x=-3\)

5.

\(25x-20=0\)

\(\Leftrightarrow25x=20\)

\(\Leftrightarrow x=\dfrac{4}{5}\)

7.

2x-3 = x+5

<=> 2x - x = 5+3

<=> x = 8

8.

x-8=2x+3

<=> x - 2x = 3+8

<=> -x = 11

<=> x = -11

9. 17-2x = 3x-5

<=> -2x-3x = -5-17

<=> -5x = -22

<=> x = \(\dfrac{22}{5}\)

10.

2x+x+22=0

<=> 3x+22=0

<=> 3x = -22

<=> x = \(\dfrac{-22}{3}\)

Mấy bài kia tự giải tương tự nhá!!!

11.

x-3=3x+5

<=> x-3x=5+3

<=> -2x=8

<=> x = -4

12. 15x + 1/2 = 0

<=> 15x = -1/2

<=> x = -1/30

13.

3x+1 = 7x-11

<=> 3x-7x = -11-1

<=> -4x=-12

<=> x = 3

14.

5-3x = 6x + 7

<=> -3x-6x = 7-12

<=> -9x = -5

<=> x = 5/9

15.

11-2x=x-1

<=> -2x-x = -1-11

<=> -3x = -12

<=> x = 4

16.

15 - 8x = 9-5x

<=> -8x+5x = 9 - 15

<=> -3x = -6

<=> x=2

17.

25-3x=4x-5

<=> -3x-4x = -5-25

<=> -7x = -30

<=> x = 30/7

18.

0,25x+1,5=0

<=> 0,25x = -1,5

<=> x = -6

19.

3x-5/6 = 1/2

<=> 3x - 5/6 = 3/6

<=> 3x-5=3

<=> 3x = 8

<=> x = 8/3

20.

-2x + 14 =0

<=> -2x = -14

<=> x = 7

a: =>x-2,7=0,3 hoặc x-2,7=-0,3

=>x=3 hoặc x=2,4

b: =>|x+1,5|=2,4

=>x+1,5=2,4 hoặc x+1,5=-2,4

=>x=-3,9 hoặc x=0,9

c: =>|2x-3|=1/6

=>2x-3=1/6 hoặc 2x-3=-1/6

=>2x=19/6 hoặc 2x=17/6

=>x=17/12 hoặc x=19/12

d: =>3|2x-5|=7,5+0,8=8,3

=>|2x-5|=83/30

=>2x-5=83/30 hoặc 2x-5=-83/30

=>2x=233/30 hoặc 2x=67/30

=>x=233/60 hoặc x=67/60

e: =>x-y=0 và y+9/25=0

=>x=y=-9/25