\(\text{n) 3-|2x-1|=(-5)}\)

\(\Rightarrow\left|2x-1\right|=3-\left(-5\right)=8\)

\(\Rightarrow\orbr{\begin{cases}2x-1=8\\2x-1=-8\end{cases}\Rightarrow\orbr{\begin{cases}x=\frac{9}{2}\\x=-\frac{7}{2}\end{cases}}}\)

\(\text{o) 12+|3-x|=9}\)

\(\Rightarrow\left|3-x\right|=9-12\)

\(\Rightarrow\left|3-x\right|=-3\)

\(\Rightarrow\text{Phương trình vô nghiệm }\)

\(\text{p) |x+9|=12+(-9)+2}\)

\(\Rightarrow\left|x+9\right|=5\)

\(\Rightarrow\orbr{\begin{cases}x+9=5\\x+9=-5\end{cases}\Rightarrow\orbr{\begin{cases}x=-4\\x=-14\end{cases}}}\)

\(\text{q) |x+5|-5=4-(-3)}\)

\(\Rightarrow\left|x+5\right|-5=7\)

\(\Rightarrow\left|x+5\right|=7+5=12\)

\(\Rightarrow\orbr{\begin{cases}x+5=12\\x+5=-12\end{cases}\Rightarrow\orbr{\begin{cases}x=7\\x=-17\end{cases}}}\)

\(\text{h) -|-5|-(-x)+4=3-(-25)}\)

\(\Rightarrow\text{-5+x+4=3+25 }\)

\(\Rightarrow\text{x=3+25+5-4}\)

\(\Rightarrow\text{x=29}\)

Học tốt

@@@Huyền2k7

n) 3-|2x-1|=(-5)
|2x-1|=3-(-5)
|2x-1|=8
\(\hept{\begin{cases}2x-1=8\\2x-1=-8\end{cases}}\)=>\(\hept{\begin{cases}2x=9\\2x=-7\end{cases}}\)=> \(\hept{\begin{cases}x=\frac{9}{2}\\x=\frac{-7}{2}\end{cases}}\)

o) 12+|3-x|=9
|3-x|=9-12
|3-x|=-3
Vì |3-x|\(\ge0\)=> |3-x| không thể bằng -3
=>\(x\in\varnothing\)

p) |x+9|=12+(-9)+2
|x+9|=5
\(\Rightarrow\hept{\begin{cases}x+9=5\\x+9=-5\end{cases}}\Leftrightarrow\hept{\begin{cases}x=-4\\x=-14\end{cases}}\)

q) |x+5|-5=4-(-3)
|x+5|-5=7
=> |x+5|=12\(\Rightarrow\hept{\begin{cases}x+5=12\\x+5=-12\end{cases}}\Leftrightarrow\hept{\begin{cases}x=7\\x=-17\end{cases}}\)

h) -|-5|-(-x)+4=3-(-25)
-5+x+4=3+15
x-1=18
x=19
Chúc bạn học tốt nhé!

n)=>|2x-1|=3-(-5)

=>2x-1=8

=>2x=8+1

=>x=\(\frac{9}{2}\)

o)=>|3-x|=9-12

=>3-x=-3

=>x=3-(-3)=6

p)=>|x+9|=5

=>x+9=5

=>x=5-9=-4

q)=>|x+5|=-4-(-3)-5

=>x+5=2

=>x=2-5=-3

h)=-5+x+4=3+25

=>x=3+25+5-4=29

hok tốt

tìm x biết:

(3x-1) [- 1/2x+5]=0

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

[2x+3/5]² - 9/25=0

-5(x+1/5)-1/2(x-2/3)=3/2x - 5 /6

[x+1/2]x [2/3-2x]=0

17/2-|2x-3/4|=-7/4

2/3x-1/2x =5/12

(x+1/5)²+17/25=26/25

[x.44/7+3/7].11/5-3/7=-2

3[3x-1/2]+1/9=0

Toán lớp 6Tìm x

 Trả lời  Câu hỏi tương tự

Chưa có ai trả lời câu hỏi này,bạn hãy là người đâu tiên giúp nguyenvanhoang giải bài toán này !

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

a) 5 - 4x = 3x - 9

\(\Leftrightarrow5-4x-3x+9=0\)

\(\Leftrightarrow14-7x=0\)

\(\Leftrightarrow7x=14\Leftrightarrow x=2\)

Vậy \(S=\left\{2\right\}\)

b) \(\left(x-4\right)\left(3x+9\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x-4=0\\3x+9=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-3\end{matrix}\right.\)

Vậy \(S=\left\{-3;4\right\}\)

c) \(\dfrac{x}{x+4}+\dfrac{12}{x-4}=\dfrac{4x+48}{x\cdot x-16}\)(1)

ĐKXĐ: \(x\ne\pm4\)

\(\left(1\right)\Leftrightarrow\dfrac{x\left(x-4\right)+12\left(x+4\right)-4x-48}{\left(x+4\right)\left(x-4\right)}=0\)

\(\Leftrightarrow x^2-4x+12x+48-4x-48=0\)

\(\Leftrightarrow x^2+4x=0\)

\(\Leftrightarrow x\left(x+4\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x+4=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(TM\right)\\x=-4\left(KTM\right)\end{matrix}\right.\)

Vậy \(S=\left\{0\right\}\)

d) \(4-2x=7-x\)

\(\Leftrightarrow4-2x-7+x=0\)

\(\Leftrightarrow-x-3=0\)

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

Vậy \(S=\left\{-3\right\}\)

e) \(\left(x+4\right) \left(8-4x\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x+4=0\\8-4x=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-4\\x=2\end{matrix}\right.\)

Vậy \(S=\left\{-4;2\right\}\)

f) \(\dfrac{x}{x+5}+\dfrac{11}{x-5}=\dfrac{x+55}{x\cdot x-25}\left(2\right)\)

ĐKXĐ: \(x\ne\pm5\)

\(\left(2\right)\Leftrightarrow\dfrac{x\left(x-5\right)+11\left(x+5\right)-x-55}{\left(x+5\right)\left(x-5\right)}=0\)

\(\Leftrightarrow x^2-5x+11x+55-x-55=0\)

\(\Leftrightarrow x^2+5x=0\)

\(\Leftrightarrow x\left(x+5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}x=0\\x+5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\left(TM\right)\\x=-5\left(KTM\right)\end{matrix}\right.\)

Vậy \(S=\left\{0\right\}\)

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

\(\Leftrightarrow\dfrac{3\left(3x+2\right)-3x-1-10-12x}{6}=0\)

\(\Leftrightarrow9x+6-3x-1-10-12x=0\)

\(\Leftrightarrow-6x-5=0\)

\(\Leftrightarrow-6x=5\)

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

Vậy \(S=\left\{-\dfrac{5}{6}\right\}\)

h) \(2x-\left(3-5x\right)=4\left(x+3\right)\)

\(\Leftrightarrow2x-3+5x-4x-12=0\)

\(\Leftrightarrow3x-15=0\)

\(\Leftrightarrow x=5\)

Vậy \(S=\left\{5\right\}\)

i) \(3x-6+x=9-x\)

\(\Leftrightarrow3x-6+x-9+x=0\)

\(\Leftrightarrow5x-15=0\)

\(\Leftrightarrow x=3\)

Vậy \(S=\left\{3\right\}\)

k)\(2t-3+5t=4t+12\)

\(\Leftrightarrow2t-3+5t-4t-12=0\)

\(\Leftrightarrow3t-15=0\)

\(\Leftrightarrow t=5\)

Vậy \(S=\left\{5\right\}\)

nhiều quá :((

\(a,2\left(x-5\right)-3\left(x+7\right)=14\)

\(2x-10-3x-21=14\)

\(-x-31=14\)

\(-x=45\)

\(x=45\)

\(b,5\left(x-6\right)-2\left(x+3\right)=12\)

\(5x-30-2x-6=12\)

\(3x-36==12\)

\(3x=48\)

\(x=16\)

\(c,3\left(x-4\right)-\left(8-x\right)=12\)

\(3x-12-8+x=0\)

\(4x-20=0\)

\(4x=20\)

\(x=5\)

Cố nốt nha bn ! 

cảm ơn, bn nha:)))

mà hình như bạn TOP 3 trả lời câu hỏi pải ko nhỉ???

d, \(-7\left(3x-5\right)+2\left(7x-14\right)=28\)

\(\Leftrightarrow-21x+35+14x-28=28\Leftrightarrow-7x=21\Leftrightarrow x=-3\)

e, \(5\left(3-2x\right)+5\left(x-4\right)=6-4x\)

\(\Leftrightarrow15-6x+5x-20=6-4x\Leftrightarrow-5-x=6-4x\)

\(\Leftrightarrow-11+3x=0\Leftrightarrow x=\frac{11}{3}\)

f, \(-5\left(2-x\right)+4\left(x-3\right)=10x-15\)

\(\Leftrightarrow-10+5x+4x-12=10x-15\Leftrightarrow-22+9x=10x-15\)

\(\Leftrightarrow-7-x=0\Leftrightarrow x=-7\)

\(a,-5.\left(-x+7\right)-3.\left(-x-5\right)=-4.\left(12-x\right)+48\)

                          \(5x-35-3x+15=-48+4x+48\)

                                                \(2x-10=4x\)

                                                \(2x-4x=10\)

                                                       \(-2x=10\)

                                                             \(x=-5\)

 \(b,\left(-x-7\right)-5.\left(-x-3\right)=12.\left(3-x\right)\)

                  \(-x-7+5x+15=36-12x\)

                                         \(4x+8=36-12x\)

                                    \(4x+12x=36-8\)

                                               \(16x=28\)

                                                    \(x=1,75\)

các câu còn lại tương tự nha

a) x=7

b)x=2/3

c)x=-13

d)x=3

e)x=-1

a ) \(-5\times\left(-x+7\right)-3\times\left(-x-5\right)=-4\times\left(12-x\right)+48\)

\(\Leftrightarrow5x-35+3x+15=-48+4x+48\)

\(\Leftrightarrow5x-3x+4x=35-15-48+48\)

\(\Leftrightarrow2x=20\)

\(\Leftrightarrow x=10\)

b ) \(-2\times\left(15-3x\right)-4\times\left(-7x+8\right)=-5-9\times\left(-2x+1\right)\)

\(\Leftrightarrow-30+6x-28x-32=-5+18x-9\)

\(\Leftrightarrow6x-28x-18x=30+32-5-9\)

\(\Leftrightarrow-40x=48\)

\(\Leftrightarrow x=-1.2\)

C,D nưã bạn

 c, 7 . ( - x - 7 ) - 5 . ( - x - 3 ) = 12 . ( 3 - x)

<=> - 7x - 49  + 5x  + 15 = 36 - 12x

<=>  - 2x + 12x = 36 - 15 + 49

<=> 10 x = 70

<=> x = 7

Vẫy  x = 7

d, 5 . ( - 3x - 7 ) - 4 . ( - 2x - 11 ) = 7 . ( 4x + 10) + 9

<=> - 15x + 8x + 44 = 28x + 70 + 9

<=> - 7x + 44 = 28x + 79

<=> - 7x - 28x = 79 - 44

<=> - 35x = 35

<=> x = - 1

Vậy x = - 1

Hc tốt