a ) x/4 = 16/128

Áp dụng tính chất phân số bằng nhau ta có 4 . 16 = x . 128 

64 = x . 128

=> x = 0,5 

b ) \(1\frac{5}{6}=\frac{-x}{5}\)

 11/6 = -x/5

Áp dụng tính chất phân số bằng nhau ta có 11 . 5 = 6 . -x

=> không tồn tại x  ( vì 11 . 5 kết quả là dương , 6 . -x sẽ có kết quả âm , dương không thể bằng âm

c ) 4,25 : 8 = -3,5 : x

    4,25 = -3.5 . 17/-14 

=> 8 = x . 17/-14

=> x = -112/17

bai 2:

x.128=16.4

x.128=64

x=64:128=1/2

b,11.5=-6x

55=-6x

x=-55/6

c,17/32=-3,5:x

x= -96/85                                                                                                                                                                                                                                         

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bai 2:

x.128=16.4

x.128=64

x=64:128=1/2

b,11.5=-6x

55=-6x

x=-55/6

c,17/32=-3,5:x

x= -96/85

\(\frac{x}{4}=\frac{16}{128}\)

\(x=\frac{16\times4}{128}\)

\(x=\frac{1}{2}\)

***

\(1^5_6=-\frac{x}{5}\)

\(\frac{x}{5}=-\frac{11}{6}\)

\(x=-\frac{11\times5}{6}\)

\(x=-\frac{55}{6}\)

***

\(4,25\div8=3,5\div x\)

\(\frac{3,5}{x}=\frac{4,25}{8}\)

\(x=\frac{3,5\times8}{4,25}\)

\(x=\frac{112}{17}\)

a) \(\frac{x}{4}=\frac{16}{128}=\frac{1}{8}\)

=> 8x = 4

=> x = 4 : 8 \(=\frac{1}{2}\)

b) \(1\frac{5}{6}=\frac{-x}{5}\)

=> \(\frac{11}{6}=\frac{-x}{5}\)

=> 11.5 = -x.6

=> 55 = x.(-6)

=> \(x=\frac{55}{-6}=-\frac{55}{6}\)

c) 4,25 : 8 = 3,5 : x

=> \(\frac{17}{4}.\frac{1}{8}=\frac{7}{2}:x\)

=> \(\frac{17}{32}=\frac{7}{2}:x\)

=> \(x=\frac{7}{2}:\frac{17}{32}\)

=> \(x=\frac{7}{2}.\frac{32}{17}=\frac{112}{17}\)

a)

\(\frac{x}{4}=\frac{16}{128}\)

\(\Rightarrow128x=64\)

\(\Rightarrow x=\frac{1}{2}\)

Vậy \(x=\frac{1}{2}\)

b) 

\(1\frac{5}{6}=\frac{-x}{5}\)

\(\Rightarrow\frac{11}{6}=-\frac{x}{5}\)

\(\Rightarrow-6x=55\)

\(\Rightarrow x=-\frac{55}{6}\)

Vậy \(x=-\frac{55}{6}\)

c)

\(4,25:8=3,5:x\)

\(\Rightarrow4,25.x=8.3,5\)

\(\Rightarrow4,25.x=28\)

\(\Rightarrow x=\frac{112}{17}\)

Vậy \(x=\frac{112}{17}\)

Chúc bạn hok tốt 

a) \(\frac{x}{4}=\frac{16}{128}\)

\(x.128=4.16\)

\(x.128=64\)

\(x=64:128\)

\(x=\frac{1}{2}\)

Vậy \(x=\frac{1}{2}\)

b) \(\frac{11}{6}=\frac{-x}{5}\)

\(11.5=\left(-x\right).6\)

\(55=\left(-x\right).6\)

\(-x=55:6\)

\(-x=\frac{55}{6}\)

\(\Rightarrow x=-\frac{55}{6}\)

Vậy \(x=-\frac{55}{6}\)

c) \(4,25:8=-3,5:x\)

\(\frac{17}{32}=-3,5:x\)

\(x=\frac{-35}{10}:\frac{17}{32}\)

\(x=-6\frac{10}{17}\)

Vậy \(x=-6\frac{10}{17}\)

\(a.\)

\(\frac{x}{4}=\frac{16}{128}\)

\(\Rightarrow x=\frac{16.4}{128}\)

\(\Rightarrow x=\frac{1}{2}\)

Vậy :       \(x=\frac{1}{2}\)

\(b.\)

\(\frac{11}{6}=\frac{-x}{5}\)

\(\Rightarrow x=\frac{11.5}{-6}\)

\(\Rightarrow x=-\frac{55}{6}\)

Vậy :        \(x=-\frac{55}{6}\)

\(c.\)

\(\frac{4,25}{8}=\frac{-3,5}{x}\)

\(\Rightarrow x=\frac{-3,5.8}{4,25}\)

\(\Rightarrow x=-6\frac{10}{7}\)

Vậy :         \(x=-6\frac{10}{7}\)

a) \(\dfrac{x}{4}=\dfrac{16}{128}\Rightarrow x=\dfrac{4.16}{128}=\dfrac{1}{2}=0,5\)

b)\(1\dfrac{5}{6}=\dfrac{-x}{5}\\ \Leftrightarrow\dfrac{11}{6}=\dfrac{-x}{5}\Rightarrow-x=\dfrac{5.11}{6}=\dfrac{55}{6}\Rightarrow x=-\dfrac{55}{6}\)

c) \(\dfrac{4,25}{8}=\dfrac{-3,5}{x}\Rightarrow x=\dfrac{8.\left(-3,5\right)}{4,25}=-\dfrac{112}{17}\)

a,X/4=16/28

=»x/4=4/7

=4/7.4

=7

b,1/5/6=-x/5

-x/5=11/6

X=11/6.5

X=55/6

a)\(\dfrac{x}{4}=\dfrac{16}{128}\)

\(\Leftrightarrow\dfrac{x}{4}=\dfrac{1}{8}\)

\(\Rightarrow x=\dfrac{1.4}{8}=\dfrac{1}{2}\)

b)\(1\dfrac{5}{6}=\dfrac{-x}{5}\)

\(\Leftrightarrow\dfrac{11}{6}=\dfrac{-x}{5}\)

\(\Rightarrow-x=\dfrac{11.5}{6}=\dfrac{-55}{6}\)

c)\(4,25:8=-3,5:x\)

\(\Leftrightarrow\dfrac{17}{32}=\dfrac{-3,5}{x}\)

\(\Rightarrow x=\dfrac{\left(-3,5\right).32}{17}=-\dfrac{112}{17}\)

Tìm x

a)\(\dfrac{x}{4}\)=\(\dfrac{16}{128}\)

\(\Rightarrow\)x.128=16.4

x.128=64

x=64:128

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

Vậy x=\(\dfrac{1}{2}\)

b)\(1\dfrac{5}{6}\)=\(\dfrac{-x}{5}\)

\(\dfrac{11}{6}\)=\(\dfrac{-x}{5}\)

-x:5=\(\dfrac{11}{6}\)

-x=\(\dfrac{11}{6}\).5

-x=\(\dfrac{55}{6}\)

\(\Rightarrow\)x=\(\dfrac{-55}{6}\)

Vậy x=\(\dfrac{-55}{6}\)

c)4,25:8 = -3,5:x

-3,5:x=\(\dfrac{17}{4}\)

x=-3,5:\(\dfrac{17}{4}\)

x=\(\dfrac{14}{17}\)

Vậy x=\(\dfrac{14}{17}\)

a, Ta có : \(\dfrac{x}{4}\)= \(\dfrac{16}{128}\)

\(\Rightarrow\)4 . 16 = x . 128

\(\Rightarrow\) x = (4 . 16 ) : 128

\(\Rightarrow\) x = \(\dfrac{1}{2}\)

b, Ta có : 1\(\dfrac{5}{6}\) = \(\dfrac{-x}{5}\)

\(\Leftrightarrow\dfrac{11}{6}\) = \(\dfrac{-x}{5}\)

\(\Rightarrow\)11 . 5 = 6 . ( \(-x\) )

\(\Rightarrow\)\(-x\) = (11. 5) : 6

\(\Rightarrow\) \(-x\) = \(\dfrac{-55}{6}\)

\(\Rightarrow\) \(x\) = \(\dfrac{55}{6}\)

c,Ta có : 4 , 25 : 8 = \(-3,5\) : x

\(\Rightarrow\) \(\dfrac{17}{32}\) = \(\dfrac{-3,5}{x}\)

\(\Rightarrow\) 17 . x = \(-3,5\) . 32

\(\Rightarrow\) x = ( \(-3,5\) . 32 ): 17

\(\Rightarrow\) x = \(\dfrac{-112}{17}\)

\(a,\dfrac{x}{4}=\dfrac{16}{128}\\ \Leftrightarrow128x=4.16\\ \Leftrightarrow128x=64\\ \Leftrightarrow x=\dfrac{1}{2}\)

Vậy...

\(b,1\dfrac{5}{6}=\dfrac{-x}{5}\\ \Leftrightarrow-6x=25\\ \Leftrightarrow x=-\dfrac{25}{6}\)

Vậy...

\(c,4,25:8=-3,5:x\\ \Leftrightarrow4,25x=-3,5.8\\ \Leftrightarrow x=-28:4,25\\ \Leftrightarrow x=-\dfrac{112}{17}\)

Vậy...

Câu a :

\(\dfrac{x}{4}=\dfrac{16}{128}\) \(\Leftrightarrow x.128=4.16\) \(\Rightarrow x=\dfrac{1}{2}\)

Câu b :

\(1\dfrac{5}{6}=-\dfrac{x}{5}\) \(\Leftrightarrow11.5=-x.6\) \(\) \(\Rightarrow-x=-\dfrac{55}{6}\)

Câu c :

\(\dfrac{4,25}{8}=\dfrac{-3,5}{x}\) \(\Leftrightarrow4,25.x=8.-3,5\) \(\Rightarrow x=-\dfrac{112}{17}\)

a,Ta có : x.128=16.4

x.128=64

Suy ra : x=1/2

b,\(1\dfrac{5}{6}=\dfrac{11}{6}\)

Ta có ; 11.5=-x.6

-x.6=55

Suy ra : x=-55/6

c,Ta có : 4,25.x=-3,5.8

4,25.x=-28

Suy ra : x=-112/17

\(3\frac{1}{2}-\frac{1}{2}.\left(-4,25-\frac{3}{4}\right)^2:\frac{5}{4}\)

\(=\frac{7}{2}-\frac{1}{2}.\left(-4,25-0,75\right)^2:\frac{5}{4}\)

\(=\frac{7}{2}-\frac{1}{2}.\left(-5\right)^2:\frac{5}{4}\)

\(=\frac{7}{2}-\frac{1}{2}.5.\frac{4}{5}\)

\(=\frac{7}{2}-2\)

\(=\frac{7}{2}-\frac{4}{2}\)

\(=\frac{3}{2}\)

\(\frac{3}{7}.1\frac{1}{2}+\frac{3}{7}.0,5-\frac{3}{7}.9\)

\(=\frac{3}{7}.\left(\frac{3}{2}+\frac{1}{2}-9\right)\)

\(=\frac{3}{7}.\left(2-9\right)\)

\(=\frac{3}{7}.\left(-7\right)\)

\(=-3\)

\(\frac{125^{2016}.8^{2017}}{50^{2017}.20^{2018}}=\frac{\left(5^3\right)^{2016}.\left(2^3\right)^{2017}}{\left(5^2\right)^{2017}.2^{2017}.\left(2^2\right)^{2018}.5^{2018}}=\frac{\left(5^3\right)^{2016}.\left(2^3\right)^{2017}}{\left(5^3\right)^{2017}.\left(2^3\right)^{2017}.2.5}=\frac{1}{5^4.2}=\frac{1}{1250}\)( tính nhẩm, ko chắc đúng )

1 

a) \(3\frac{1}{2}-\frac{1}{2}\cdot\left(-4,25-\frac{3}{4}\right)^2\) : \(\frac{5}{4}\)

= \(3\cdot25:\frac{5}{4}\)

= \(3\cdot\left(25:\frac{5}{4}\right)\)

=\(3\cdot20\)

=60

b)=\(\frac{3}{7}\cdot\left(1\frac{1}{2}+0,5-9\right)\)

=\(\frac{3}{7}\cdot\left(-7\right)\)

=\(-3\)

c) =