Giải:

a) \(\dfrac{-5}{8}=\dfrac{x}{16}\) 

\(\Rightarrow x=\dfrac{16.-5}{8}=-10\) 

\(\dfrac{3x}{9}=\dfrac{2}{6}\) 

\(\Rightarrow3x=\dfrac{2.9}{6}=3\) 

\(\Rightarrow x=1\)

b) \(\dfrac{x+3}{15}=\dfrac{1}{3}\)  

\(\Rightarrow x+3=\dfrac{1.15}{3}=5\) 

\(\Rightarrow x=2\)

\(\dfrac{6}{2x+1}=\dfrac{2}{7}\) 

\(\Rightarrow2x+1=\dfrac{6.7}{2}=21\) 

\(\Rightarrow x=10\)

c) \(\dfrac{4}{x-6}=\dfrac{y}{24}=\dfrac{-12}{18}\) 

\(\Rightarrow\dfrac{4}{x-6}=\dfrac{-12}{18}\) 

\(\Rightarrow x-6=\dfrac{18.4}{-12}=-6\) 

\(\Rightarrow x=0\) 

\(\Rightarrow\dfrac{y}{24}=\dfrac{-12}{18}\) 

\(\Rightarrow y=\dfrac{-12.24}{18}=-16\) 

 \(\dfrac{3-x}{-12}=\dfrac{16}{y+1}=\dfrac{192}{-72}\) 

\(\Rightarrow\dfrac{3-x}{-12}=\dfrac{192}{-72}\) 

\(\Rightarrow3-x=\dfrac{192.-12}{-72}=32\) 

\(\Rightarrow x=-29\) 

\(\Rightarrow\dfrac{16}{y+1}=\dfrac{192}{-72}\) 

\(\Rightarrow y+1=\dfrac{16.-72}{192}=-6\) 

d) \(\dfrac{-2}{3}< \dfrac{x}{5}< \dfrac{-1}{6}\) 

\(\Rightarrow\dfrac{-20}{30}< \dfrac{6x}{30}< \dfrac{-5}{30}\) 

\(\Rightarrow6x\in\left\{-18;-12;-6\right\}\) 

\(\Rightarrow x\in\left\{-3;-2;-1\right\}\) 

\(\dfrac{-1}{5}\le\dfrac{x}{8}\le\dfrac{1}{4}\) 

\(\Rightarrow\dfrac{-8}{40}\le\dfrac{5x}{40}\le\dfrac{10}{40}\) 

\(\Rightarrow5x\in\left\{-5;0;5;10\right\}\) 

\(\Rightarrow x\in\left\{-1;0;1;2\right\}\) 

e) \(\dfrac{x+46}{20}=x\dfrac{2}{5}\) 

\(\Rightarrow\dfrac{x+46}{20}=x+\dfrac{2}{5}\) 

\(\Rightarrow\dfrac{x+46}{20}=\dfrac{5x+2}{5}\) 

\(\Rightarrow5.\left(x+46\right)=20.\left(5x+2\right)\) 

\(\Rightarrow5x+230=100x+40\) 

\(\Rightarrow5x-100x=40-230\) 

\(\Rightarrow-95x=-190\) 

\(\Rightarrow x=-190:-95\) 

\(\Rightarrow x=2\) 

\(y\dfrac{5}{y}=\dfrac{86}{y}\) 

\(\Rightarrow y+\dfrac{5}{y}=\dfrac{86}{y}\) 

\(\Rightarrow\dfrac{y^2+5}{y}=\dfrac{86}{y}\) 

\(\Rightarrow y^2+5=86\) 

\(\Rightarrow y^2=86-5\) 

\(\Rightarrow y^2=81\) 

\(\Rightarrow\left[{}\begin{matrix}y=9\\y=-9\end{matrix}\right.\) 

Chúc bạn học tốt!

\(x=\dfrac{7}{25}+\dfrac{-1}{5}=\dfrac{7}{25}-\dfrac{1}{5}=\dfrac{2}{25}.\\ x=\dfrac{5}{11}+\dfrac{4}{-9}=\dfrac{5}{11}-\dfrac{4}{9}=\dfrac{1}{99}.\\ \dfrac{5}{9}-\dfrac{x}{-1}=\dfrac{-1}{3}\Leftrightarrow\dfrac{5}{9}+x=-\dfrac{1}{3}.\Leftrightarrow x=-\dfrac{8}{9}.\)

\(x=\dfrac{7}{25}+-\dfrac{1}{5}=>\dfrac{7}{25}+-\dfrac{5}{25}=>x=\dfrac{2}{25}\)

\(x=\dfrac{5}{11}+\dfrac{4}{-9}=>\dfrac{-45}{-99}+\dfrac{44}{-99}=>x=\dfrac{-1}{-99}=\dfrac{1}{99}\)

\(\dfrac{5}{9}-\dfrac{x}{-1}=-\dfrac{1}{3}=>-\dfrac{1}{3}-\dfrac{5}{9}=>\dfrac{x}{-1}=-\dfrac{8}{9}=>x=-\dfrac{8}{9}\)

a: \(\dfrac{-8}{3}\cdot\dfrac{15}{24}=\dfrac{-8}{24}\cdot\dfrac{15}{3}=\dfrac{-1}{3}\cdot5=-\dfrac{5}{3}\)

b: \(=\dfrac{3}{4}\cdot\dfrac{1}{-9}=\dfrac{-1}{12}\)

c: \(x=-\dfrac{7}{6}+\dfrac{5}{8}=-\dfrac{13}{24}\)

d: \(x=-\dfrac{14}{25}-\dfrac{3}{4}=\dfrac{-56-75}{100}=\dfrac{-131}{100}\)

1) \(\Rightarrow x^2\left(x^{2004}-1\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x=0\\x^{2004}=1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=0\\x=1\\x=-1\end{matrix}\right.\)

2) \(\Rightarrow\left(x-5\right)^4\left[\left(x-5\right)^2-1\right]=0\)

\(\Rightarrow\left[{}\begin{matrix}x-5=0\\\left(x-5\right)^2=1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=5\\x-5=1\\x-5=-1\end{matrix}\right.\)\(\Rightarrow\left[{}\begin{matrix}x=5\\x=6\\x=4\end{matrix}\right.\)

a: =>x=-7/6+5/8=-13/24

b: =>x=-14/25-3/4=-131/100

c: \(x=\dfrac{-33}{26}:\dfrac{-9}{13}=\dfrac{33}{26}\cdot\dfrac{13}{9}=\dfrac{11}{3}\cdot\dfrac{1}{2}=\dfrac{11}{6}\)

d: \(x=\dfrac{4}{9}:\dfrac{5}{3}=\dfrac{4}{9}\cdot\dfrac{3}{5}=\dfrac{12}{45}=\dfrac{4}{15}\)

a,1/4

b,8

a, 1/4
b,8

`a) 3-5+(-x+3)=6`

`=>5+(-x+3)=3-6`

`=>5+(-x+3)=-3`

`=>-x+3=-3-5`

`=>-x+3=-8`

`=>-x=-8-3`

`=>-x=-11`

`=>x=11`

__

`b)(-4-x)+(4-15)=-15`

`=>(-4-x)+-11=-15`

`=>-4-x=-15-(-11)`

`=>-4-x=-15+11`

`=>-4-x=-4`

`=>x=-4-(-4)`

`=>x=-4+4`

`=>x=0`

`c)(11+x)-(-11-9)=32`

`=>(11+x)-(-20)=32`

`=>(11+x)+20=32`

`=>11+x=32-20`

`=>11+x=12`

`=>x=12-11`

`=>x=1`

`a)3-5+(-x+3)=6`

`5+(-x+3)=3-6`

`5+(-x+3)=-3`

`-x+3=-3-5`

`-x+3=-8`

`-x=-8-3`

`-x=-11`

`x=11`

`b,(-4-x)+(4-15)=-15`

`(-4-x)+(-11)=-15`

`-4-x=-15-(-11)`

`-4-x=-15+11`

`-4-x=-4`

`x=-4-(-4)`

`x=-4+4`

`x=0`

`c)(11+x)-(-11-9)=32`

`(11+x)-(-20)=32`

`(11+x)+20=32`

`11+x=32-20`

`11+x=12`

`x=12-11`

`x=1`

\(a,x\in\left\{-5;-4;-3;-2;-1\right\}\\ b,x\in\left\{-3;-2;-1;...;5;6\right\}\\ c,x\in\left\{-4;-3;...;3;4\right\}\\ d,x\in\left\{-3;-2;-1;0;1;2\right\}\)

a: Ta có: \(71-\left(x+33\right)=26\)

\(\Leftrightarrow x+33=45\)

hay x=12

b: Ta có: \(\left(x+73\right)-26=76\)

\(\Leftrightarrow x+73=102\)

hay x=29

c: Ta có: \(45-\left(x+9\right)=6\)

\(\Leftrightarrow x+9=39\)

hay x=30

a) 71 - ( 33 + x ) = 26

(33 + x ) = 71 -26

33 + x = 45

x        = 45 - 33 = 12

b) ( x + 73 ) - 26 = 76

    ( x + 73 )        = 102

    x                     = 102 - 73 = 29

c) 45 - ( x + 9 ) = 6

 ( x + 9 )           = 45 - 6 = 39

 x                      = 39 - 9 = 30

d) 89 - ( 73 - x ) = 20 

 73 - x  = 89 - 20

73 - x = 69

x          = 73 - 69 = 4

e) 4(x+41) = 400

   x + 41 = 400 : 4 = 100

   x = 100 - 41 = 59

f) 11(x-9 ) = 77

     x - 9 = 77 : 11 = 7

    x = 7 + 9 = 16

g) x + 7 = 25 + 13 = 38

    x = 38 - 7 = 31

h) x + 4 = 198 - 120 = 78

   x = 78 - 4 = 74

i) x - 9 = 350 : 5 = 70

   x = 70 + 9 = 79

j) 2x - 49 = 5 . 9 = 45

   2x = 45 + 49 = 94

   x = 94 : 2 = 47

k) 25 + 3( x - 8 ) = 106

    3(x-8 ) = 106 - 25 = 81

   x - 8 = 81 : 3 = 27 

x = 27 +8= 35

l) 9( x + 4 ) - 25 = 20

   9( x + 4 ) = 20 + 25 = 45

     x + 4 =45 : 9 = 5

   x = 5 - 4 = 1

m) 200 - ( 2x + 6 ) = 64

     2x + 6 = 200 - 64 = 136

   2x = 136 - 6 = 130

x = 130 : 2 = 65