***c,4(x-5)-3(x+7)=-19

Suy ra (4x-20)-(3x+21)=-19

Suy ra (4x-3x)-(20+21)=-19

Suy ra x-41=-19

suy ra x=-19+41

Suy ra x=22

Vậy x=22

a) 4/5.x=4/7
=>x=4/7:4/5
=>x=4/7.5/4
=>x=5/7
b) x:8/11=11/3
=>x=11/3.8/11
=>x=8/3
c)4/5+5/7:x=1/6
=>5/7:x=1/6-4/5
=>5/7:x=-19/30
=>x=5/7:(-19/30)
=>x=-150/133
d)2/9-7/8.x=1/3
=>7/8.x=2/9-1/3
=>7/8.x=-1/9
=>x=-1/9:7/8
=>x=-8/63
nhớ đ-ú-n-g nha

Bài 1 :

\(a)x=\frac{7}{25}+\left(-\frac{1}{5}\right)\)

    \(x=\frac{2}{25}\)

\(b)x=\frac{5}{11}+\left(\frac{4}{-9}\right)\)

    \(x=\frac{1}{99}\)

Mấy câu kia dễ tự làm :>

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???

Bài 1:

a: \(x=\dfrac{2}{3}:\dfrac{3}{5}=\dfrac{2}{3}\cdot\dfrac{5}{3}=\dfrac{10}{9}\)

b: \(x=\dfrac{17}{8}:\dfrac{7}{17}=\dfrac{17}{8}\cdot\dfrac{17}{7}=\dfrac{289}{56}\)

c: \(x=-\dfrac{3}{4}:\dfrac{7}{12}=\dfrac{-3}{4}\cdot\dfrac{12}{7}=\dfrac{-63}{28}=-\dfrac{9}{4}\)

d: \(\Leftrightarrow x\cdot\dfrac{1}{6}=\dfrac{3}{8}-\dfrac{1}{4}=\dfrac{1}{4}\)

hay \(x=\dfrac{1}{4}:\dfrac{1}{6}=\dfrac{3}{2}\)

e: \(\Leftrightarrow\dfrac{1}{2}:x=-4-\dfrac{1}{3}=-\dfrac{17}{3}\)

hay \(x=-\dfrac{1}{2}:\dfrac{17}{3}=\dfrac{-3}{34}\)

dad

Tìm số nguyên x, biết:

a, (-4).|x+2|= -8

|x+2| = -8 : (-4)

|x+2| = 2

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

Vậy x = 0 ; x = -4

b, 4.|x+1|= 8.(-2)-8.(-5)

4.|x+1|= 8. [ (-2) - (-5) ]

4.|x+1|= 8. 3

4.|x+1|= 24

|x+1| = 6

\(\Rightarrow\left[{}\begin{matrix}x+1=6\\x+1=-6\end{matrix}\right.\) \(\Rightarrow\left[{}\begin{matrix}x=6\\x=-7\end{matrix}\right.\)

Vậy x = 6; x = -7

c, (2.x-4).(x+6)=0

\(\Rightarrow\) 2.x-4 = x + 6

\(\Rightarrow\) 2x : x = 6 + 4

\(\Rightarrow\) x = 10

d,4.(x-5)-3(x+7)= -19

\(\Rightarrow\) 4x - 20 - 3x - 21 = -19

\(\Rightarrow\) ( 4x - 3x ) - ( 20 - 21 ) = -19

\(\Rightarrow\) x - (-1) = -19

\(\Rightarrow\) x + 1 = -19

\(\Rightarrow\) x = -19 - 1 = -20

e, 3.(x-4)-(8-x)=12

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

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

\(\Rightarrow\) 4x - 20 = 12

\(\Rightarrow\) 4x = 32

\(\Rightarrow\) x = 8

f, 7.(x-3)-5.(3-x)=11.x-5

\(\Rightarrow\) 7x - 21 - 5x - 15 = 11x - 5

\(\Rightarrow\) 12x - 36 = 11x - 5

\(\Rightarrow\) 12x - 11x = -5 + 36

\(\Rightarrow\) x = 31

1. Tập xác định của phương trình

   
2. 2

   Biến đổi vế trái của phương trình

   
3. 3

   Phương trình thu được sau khi biến đổi

   
4. 4

   Lời giải thu được

   

a, (10/3:x).(-5/4)=-10/3

10/3:x=-10/3:(-5/4)

10/3:x=8/3

x=10/3:8/3

x=5/4

b,(-6/5+x):(-18/5)=-1/4

-6/5+x=-1/4.(-18/5)

-6/5+x=9/10

x=9/10-(-6/5)=9/10+6/5

x=21/10

c,-22/15.x+1/3=-2/5

-22/15.x=-2/5-1/3=-11/15

x=-11/15:(-22/15)

x=11/21

d,(0,25-30%x).1/3=-31/6+1/4=-59/12

1/4-3/10x=-59/12:1/3=-59/4

3/10x=1/4-(-59/4)=1/4+59/4=15

x=15:3/10

x=50

e,(0,5x-3/7):1/2=8/7

1/2x=8/7.1/2=4/7

x=4/7:1/2

x=8/7