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cái này đúng không nhỉ 

\(\Leftrightarrow4,5-2x=\dfrac{11}{14}:\dfrac{11}{7}\)

\(\Leftrightarrow4,5-2x=\dfrac{1}{2}\)

\(\Leftrightarrow2x=4,5-\dfrac{1}{2}\)

\(\Leftrightarrow x=4:2\)

\(\Leftrightarrow x=2\)

4,5 -2x = 11/14 : 1 4/7

4,5 -2x = 11/14 : 11/7

4,5 -2x =  1/2

2x = 4,5 - 1/2

2x = 4

x = 4 : 2

x = 2

d: =>-x-5/6=7/12-4/12=3/12=1/4

=>-x=1/4+5/6=13/12

hay x=-13/12

e: =>x+3=-5

hay x=-8

f: =>4,5-2x=-1/2

=>2x=5

hay x=5/2

a, 4,5 - 2x . 147 = 1114

2x . 147 = 4,5 - 1114

2x . 147 = -1109,5

2x = -1109,5 / 147

2x = \(-\dfrac{317}{42}\)

x = \(-\dfrac{317}{42}:2\)

x = \(-\dfrac{317}{84}\)

b, ( x + 14 - 13 ) : ( 2 + 16 - 14 ) = 746

( x + 1 ) : 4 = 746

x + 1 = 746 . 4

x + 1 = 2984

x = 2984 - 1

x = 2983

c, \(\dfrac{13}{15}-\left(\dfrac{13}{21}+x\right).\dfrac{7}{12}=\dfrac{7}{10}\)

\(\left(\dfrac{13}{21}+x\right).\dfrac{7}{12}=\dfrac{13}{15}-\dfrac{7}{10}\)

\(\left(\dfrac{13}{21}+x\right).\dfrac{7}{12}=\dfrac{1}{6}\)

\(\dfrac{13}{21}+x=\dfrac{1}{6}:\dfrac{7}{12}\)

\(\dfrac{13}{21}+x=\dfrac{2}{7}\)

\(x=\dfrac{2}{7}-\dfrac{13}{21}\)

\(x=-\dfrac{1}{3}\)

=>4,5-2x=11/14:11/7=1/2

=>2x=4

hay x=2

\(\left(4,5-2x\right)\cdot1\dfrac{4}{7}=\dfrac{11}{14}\)

\(\left(\dfrac{9}{2}-2x\right)\cdot\dfrac{11}{7}=\dfrac{11}{14}\)

\(\dfrac{9}{2}-2x=\dfrac{11}{14}:\dfrac{11}{7}\)

\(\dfrac{9}{2}-2x=\dfrac{1}{2}\)

\(2x=\dfrac{9}{2}-\dfrac{1}{2}\)

\(2x=\dfrac{8}{2}\)

\(x=\dfrac{8}{2}:2\)

`x=2`

(4,5 - 2\(x\)) (-1\(\dfrac{4}{7}\)) = \(\dfrac{11}{14}\)

(4,5 - 2\(x\)) (-\(\dfrac{11}{7}\)) = \(\dfrac{11}{14}\)

4,5 - 2\(x\) = \(\dfrac{11}{14}\) : ( - \(\dfrac{11}{7}\))

4,5 - 2\(x\) = \(\dfrac{11}{14}\) \(\times\) (- \(\dfrac{7}{11}\))

4,5 - 2\(x\) = - \(\dfrac{1}{2}\) 

4,5 - 2\(x\) = -0,5

2\(x\) = 4,5 + 0,5

2\(x\) = 5

\(x\) = 5: 2

\(x\) = 2,5 

a, \(\left(2,8x-32\right):\dfrac{2}{3}=-90\)

\(\Rightarrow2,8x-32=-60\)

\(\Rightarrow2,8x=-28\)

\(\Rightarrow x=-10\)

Vậy x = -10

b, \(\left(4,5-2x\right):1\dfrac{4}{7}=\dfrac{11}{14}\)

\(\Rightarrow\left(4,5-2x\right):\dfrac{11}{7}=\dfrac{11}{14}\)

\(\Rightarrow4,5-2x=\dfrac{121}{98}\)

\(\Rightarrow2x=\dfrac{160}{49}\)

\(\Rightarrow x=\dfrac{80}{49}\)

Vậy \(x=\dfrac{80}{49}\)

\(a,\left(2,8x-32\right):\dfrac{2}{3}=-90\)

\(2,8x-32=-90.\dfrac{2}{3}\)

\(2,8x-32=-60\)

\(2,8x=-60+32\)

\(2,8x=-28\)

\(x=-28:2,8\)

\(x=-10\)

Vậy \(x=-10\)

\(b,\left(4,5-2x\right):1\dfrac{4}{7}=\dfrac{11}{14}\)

\(\left(4,5-2x\right):\dfrac{11}{7}=\dfrac{11}{14}\)

\(4,5-2x=\dfrac{11}{14}.\dfrac{11}{7}\)

\(4,5-2x=\dfrac{121}{98}\)

\(2x=4,5-\dfrac{121}{98}\)

\(2x=\dfrac{160}{49}\)

\(x=\dfrac{160}{49}:2\)

\(x=\dfrac{80}{49}\)

Vậy \(x=\dfrac{80}{49}\)

\(a,\left(2,8x-32\right):\dfrac{2}{3}=-90\)

\(2,8x-32\) \(=-90.\dfrac{2}{3}\)

\(2,8x-32\)