\(3,8:2x=\frac{1}{4}:2\frac{2}{3}\)

b) -0,5...">

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11 tháng 7 2016

a) - 0,52 : x = - 9,36 : 16,38

- 0,52 : x = \(-\frac{4}{7}\)

\(x=\left(-0,52\right):\left(-\frac{4}{7}\right)=\frac{91}{100}=0,91\)

b) \(\frac{4\frac{1}{4}}{2\frac{7}{8}}=\frac{x}{1,61}\)

\(\frac{\frac{17}{4}}{\frac{23}{8}}=\frac{x}{1,61}\)

\(\frac{x}{1,61}=\frac{34}{23}\)

\(x=\frac{34}{23}.1,61=2,38\)

19 tháng 7 2016

a, ta có:27:3,6=7,5

=>-2x7,5=15

vậy x cần tìm là 15

b, -0,52:x=\(-\frac{4}{7}\)

\(\frac{-13}{25}\): x=\(\frac{-4}{7}\)

x=\(\frac{-13}{25}:\frac{-4}{7}\)

x=0,91

6 tháng 10 2020

a)\(\frac{x}{27}=\frac{-2}{3,6}\)

=>x.3,6=27.(-2)

=>x.3,6=-54

=>x=-15

b)-0,52:x=-9,36:16,38

=>-0,52:x=-4/7

=>x=0,91

c)\(\frac{4\frac{1}{4}}{2\frac{7}{8}}=\frac{x}{1,61}\)

=>\(2\frac{7}{8}.x=4\frac{1}{4}.1,61\)

=>\(2\frac{7}{8}.x=\frac{2737}{400}\)

=>x=\(\frac{119}{50}\)

6 tháng 10 2020

a,\(\frac{x}{27}=-\frac{2}{3,6}\)

\(\Leftrightarrow x.3,6=27.-2\)

\(\Leftrightarrow x.3,6=-54\)

\(\Leftrightarrow x=-15\)

b,\(-0,52\div x=-9,36\div16,38\)

\(\Leftrightarrow-0,52\div x=-\frac{4}{7}\)

\(\Leftrightarrow x=\frac{91}{100}\)

c,\(\frac{4\frac{1}{4}}{2\frac{7}{8}}=\frac{x}{1,61}\)

\(\Leftrightarrow\frac{4,25}{2,875}=\frac{x}{1,61}\)

\(\Leftrightarrow x.2,875=4,25.1,61\)

\(\Leftrightarrow x.2,875=6,8425\)

\(\Leftrightarrow x=2,38\)

 
31 tháng 7 2016

\(3,8:\left(2x\right)=\frac{1}{4}:2\frac{2}{3}\)

\(3,8:\left(2x\right)=\frac{3}{32}\)

\(\Rightarrow2x=3,8:\frac{3}{32}\)

\(\Rightarrow x=\frac{608}{15}:2=\frac{304}{15}\)

31 tháng 7 2016

\(\left(a\right)\) tức là bài a hay là gt trog tỉ lệ thức v pn?

31 tháng 7 2016

\(a,-0,52:x=-9,36:16,38\)

\(\Leftrightarrow\frac{-13}{25}:x=\frac{-4}{7}\)

\(\Leftrightarrow x=\frac{-13}{25}:\frac{-4}{7}\)

\(\Leftrightarrow x=\frac{91}{100}\)

\(b,\frac{x}{-15}=\frac{-60}{x}\)

\(\Leftrightarrow x^2=900\)

\(\Leftrightarrow x^2=\left(30,-30\right)^2\)

\(\Leftrightarrow\orbr{\begin{cases}x=30\\x=-30\end{cases}}\)

\(c,\frac{-2}{x}=\frac{-x}{8}\)

\(\Leftrightarrow-\left(x^2\right)=-16\)

\(\Leftrightarrow x^2=16\)

\(\Leftrightarrow x^2=\left(4,-4\right)^2\)

\(\Leftrightarrow\orbr{\begin{cases}x=-4\\x=4\end{cases}}\)

\(d.3,8\div2x=\frac{1}{4}:2\frac{2}{3}\)

\(\Leftrightarrow3,8\div2x=\frac{3}{32}\)

\(\Leftrightarrow2x=3,8\div\frac{3}{32}\)

\(\Leftrightarrow2x=\frac{608}{15}\)

\(\Leftrightarrow x=\frac{608}{15}\div2\)

\(\Leftrightarrow x=\frac{304}{15}\)

\(e.0,25x\div3=\frac{5}{6}:0,125\)

\(\Leftrightarrow0,25x\div3=\frac{20}{3}\)

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

\(\Leftrightarrow\frac{1}{4}x=20\)

\(\Leftrightarrow x=20:\frac{1}{4}\)

\(\Leftrightarrow x=80\)

25 tháng 9 2016

\(\frac{x}{27}=-\frac{2}{3,6}\)

\(x=\frac{-2\times27}{3,6}\)

\(x=-15\)

***

\(\frac{-0,52}{x}=\frac{-9,36}{16,38}\)

\(x=\frac{-0,52\times16,38}{-9,36}\)

\(x=0,91\)

***

\(\frac{4\frac{1}{4}}{2\frac{7}{8}}=\frac{x}{1,61}\)

\(\frac{4,25}{2,875}=\frac{x}{1,61}\)

\(x=\frac{4,25\times1,61}{2,875}\)

\(x=2,38\)

25 tháng 9 2016

\(a.\)

\(\frac{x}{27}=\frac{-2}{3,6}\)

\(\Rightarrow x=\frac{\left(-2\right).27}{3,6}\)

\(\Rightarrow x=\frac{-54}{3,6}\)

\(\Rightarrow x=-15\)

Vậy :        \(x=-15\)

\(b.\)

\(-0,52:x=-9,36:16,38\)

\(\Rightarrow\frac{-0,52}{x}=-\frac{4}{7}\)

\(\Rightarrow x=\frac{-0,52.7}{-4}\)

\(\Rightarrow x=0,91\)

Vậy :         \(x=0,91\)

\(c.\)

\(\frac{4\frac{1}{4}}{2\frac{7}{8}}=\frac{x}{1,61}\)

\(\Rightarrow\frac{\frac{17}{4}}{\frac{23}{8}}=\frac{x}{1,61}\)

\(\Rightarrow\frac{17}{4}.\frac{8}{23}=\frac{x}{1,61}\)

\(\Rightarrow\frac{34}{23}=\frac{x}{1,61}\)

\(\Rightarrow x=\frac{1,61.34}{23}\)

\(\Rightarrow x=\frac{119}{50}\)

Vậy :         \(x=\frac{119}{50}\)

10 tháng 7 2016

1) a) Ta có: \(\frac{x}{-15}=\frac{-60}{x}\) \(\Rightarrow x^2=\left(-15\right).\left(-60\right)=900\)

                                               \(\Rightarrow x=30\)

b) \(\frac{-2}{x}=\frac{-x}{\frac{8}{25}}\) \(\Rightarrow x.\left(-x\right)=\left(-2\right).\frac{8}{25}\)

                               \(\Rightarrow x.\left(-x\right)=\frac{-16}{25}\)

                                \(\Rightarrow x.\left(-x\right)=\left(\frac{-4}{5}\right).\frac{4}{5}\)

Vậy \(x=\frac{4}{5}\)

2) a) \(3,8: \left(2x\right)=\frac{1}{4}:2\frac{2}{3}\)

\(\Rightarrow3,8: \left(2x\right)=\frac{3}{32}\)

\(\Rightarrow2x=\frac{3}{32}:3,8=\frac{15}{608}\)

\(x=\frac{15}{608}:2=\frac{15}{1216}\)

Vậy \(x=\frac{15}{1216}\)

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

\(\Rightarrow\left(0,25x\right):3=\frac{20}{3}\)

\(\Rightarrow0,25x=\frac{20}{3}.3=20\)

\(\Rightarrow x=20:0,25=80\)

Vậy x = 80

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

\(\Rightarrow\frac{1}{250}=\left(0,75x\right):0,75\)

\(\Leftrightarrow0,75x=\frac{1}{250}.0,75=\frac{3}{1000}\)

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

Vậy \(x=\frac{1}{250}\)

d) \(1\frac{1}{3}:0,8=\frac{2}{3}:\left(0,1x\right)\)

\(\Rightarrow\frac{5}{3}=\frac{2}{3}:\left(0,1x\right)\)

\(\Rightarrow0,1x=\frac{5}{3}.\frac{2}{3}=\frac{10}{9}\)

\(\Rightarrow x=\frac{10}{9}:0,1=\frac{100}{9}\)

Vậy \(x=\frac{100}{9}\)

10 tháng 7 2016

a) \(\frac{x}{-15}=\frac{-60}{x}\Leftrightarrow x.x=-15.\left(-60\right)\Leftrightarrow x^2=900\Leftrightarrow x^2=\orbr{\begin{cases}30^2\\\left(-30\right)^2\end{cases}}\Leftrightarrow x=\orbr{\begin{cases}30\\-30\end{cases}}\)