0,01 : 2,5 = (0,75x) : 0,75

⇔ (0,75x).2,5 = 0,01.0,75

⇔ (0,75x) = (0,01.0,75) : 2,5

⇔ 0,75x = 0,003

⇔ x = 0,003 : 0,75 ⇔ x = 0,004

a) Ta có: \(\dfrac{x}{-15}=\dfrac{-60}{x}\)

\(\Leftrightarrow x^2=\left(-15\right)\cdot\left(-60\right)=900\)

hay \(x\in\left\{30;-30\right\}\)

Vậy: \(x\in\left\{30;-30\right\}\)

b) Ta có: \(\left|x\right|+0.573=2\)

\(\Leftrightarrow\left|x\right|=1.427\)

hay \(x\in\left\{1.427;-1.427\right\}\)

Vậy: \(x\in\left\{1.427;-1.427\right\}\)

c) Ta có: \(\left|x+\dfrac{1}{3}\right|-4=-1\)

\(\Leftrightarrow\left|x+\dfrac{1}{3}\right|=3\)

\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{1}{3}=3\\x+\dfrac{1}{3}=-3\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{8}{3}\\x=-\dfrac{10}{3}\end{matrix}\right.\)

Vậy: \(x\in\left\{\dfrac{8}{3};-\dfrac{10}{3}\right\}\)

d) Ta có: \(0.01:2.5=\left(0.75x\right):0.75\)

\(\Leftrightarrow\dfrac{0.75\cdot x}{0.75}=\dfrac{0.01}{2.5}\)

\(\Leftrightarrow x=\dfrac{1}{250}\)

Vậy: \(x=\dfrac{1}{250}\)

a)\(\frac{x}{64}=-\frac{16}{x}\Rightarrow x^2=-16\cdot64\)

\(\Rightarrow x^2=-1024\)

Do \(x^2\ge0>-1024=VP\)

=>x vô nghiệm

b)0,01: 2,5= (0,75x) : 0,75

=>0,004=0,75:0,75*x

=>0,004=x

Vậy x=0,004

\(\Leftrightarrow\dfrac{1}{250}=3x\\ \Leftrightarrow x=\dfrac{1}{750}\)

\(\Leftrightarrow0,75x=\dfrac{0,25\cdot0,01}{2,5}=\dfrac{1}{1000}\\ \Leftrightarrow x=\dfrac{1}{1000}:\dfrac{3}{4}\dfrac{3}{4000}\)

Giữ lời hứa nka Nguyễn Mạnh Tân!

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Hứa k r lm cko! Bài dài lắm

( 0,25x ) : 3 = 5/6 : 0,125

( 1/4x ) : 3 = 5/6 : 1/8

( 1/4x ) : 3 = 5/6 x 8

( 1/4x ) : 3 = 20/3

1/4x          = 20/3 x 3

1/4x         = 20

x              = 20 : 1/4

x              = 80

0,01 : 2,5 = ( 0,75x ) : 0,75

1/100 : 25/10 = (3/4x) : 3/4

1/100 x 10/25 = (3/4x) : 3/4

=>(3/4x) : 3/4 = 1/250

3/4x                = 1/250 x 3/4

3/4x                = 3/1000

x                     = 3/1000 : 3/4

x                     = 1/250

 4/3 : 0,8 = 2/3 : ( 0,1x )

<=>2/3 : (0,1x) = 4/3 : 0,8

2/3 : (0,1x) = 4/3 : 4/5

2/3 : (0,1x) = 4/3 x 5/4

2/3 : (0,1x) = 5/3

2/3 : (1/10x) = 5/3

1/10x           = 2/3 : 5/3

1/10x           = 2/3 x 3/5

1/10x           = 2/5

x                  = 2/5 : 1/10

x                  = 2/5 x 10

x                  = 4

a) \(\left(0,25x\right):3=\frac{5}{6}:0,125\)

\(\Leftrightarrow0,25x=\frac{20}{3}.3\)

\(\Leftrightarrow x=80\)

b) \(0,01:2,5=\left(0,75x\right):0,75\)

\(\Leftrightarrow x=\frac{1}{250}\)

a, \(\frac{0,25x}{3}=\frac{5}{6:0,125}\Leftrightarrow\frac{0,25x}{3}=\frac{5}{48}\Leftrightarrow12x=15\Leftrightarrow x=\frac{5}{4}\)

b, \(\frac{0,01}{2,5}=\frac{0,75x}{0,75}\Leftrightarrow\frac{3}{400}=\frac{15}{8}x\Leftrightarrow x=\frac{1}{250}\)

\(\left(0,25x\right):3=\frac{5}{6}:0,125\)

=> \(0,25x=\frac{3\cdot\frac{5}{6}}{0,125}=\frac{3\cdot\frac{5}{6}}{\frac{1}{8}}=\frac{5}{2}:\frac{1}{8}=\frac{5}{2}\cdot8=20\)

=> \(x=20:0,25=80\)

Vậy x = 80

b) \(0,01:2,5=\left(0,75x\right):0,75\)

=> \(0,75x=\frac{0,75\cdot0,01}{2,5}=\frac{\frac{3}{4}\cdot\frac{1}{100}}{\frac{5}{2}}=\frac{3}{400}:\frac{5}{2}=\frac{3}{400}\cdot\frac{2}{5}=\frac{3}{1000}\)

=> \(x=\frac{3}{1000}:0,75=\frac{3}{1000}:\frac{3}{4}=\frac{3}{1000}\cdot\frac{4}{3}=\frac{1}{250}\)

Vậy x = 1/250