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

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

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

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

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

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

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

\(x=-15\)

***

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

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

\(x=0,91\)

***

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

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

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

\(x=2,38\)

\(a.\)

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

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

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

\(\Rightarrow x=-15\)

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 :         \(x=\frac{119}{50}\)

a) \(\frac{x}{27}=\frac{-2}{3,6}\Leftrightarrow x=\frac{-2.27}{3,6}=-15\)

b) \(\frac{4\frac{1}{4}}{2\frac{7}{8}}=\frac{x}{1,61}\Leftrightarrow\frac{4,25}{2,875}=\frac{x}{1,61}\Leftrightarrow x=\frac{4,25.1,61}{2,875}=2,38\)

a) \(\frac{x}{27}=-\frac{2}{3,6}\Rightarrow x=\frac{-2.27}{3,6}=-15\)

b) \(\frac{4\frac{1}{4}}{2\frac{7}{8}}=\frac{x}{1,61}\Rightarrow\frac{\frac{17}{4}}{\frac{23}{8}}=\frac{x}{1,61}\Leftrightarrow\frac{17}{4}\cdot\frac{8}{23}=\frac{x}{1,61}\)

 \(\frac{34}{23}=\frac{x}{1,61}\Rightarrow x=\frac{1,61.34}{23}=2,38\)

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

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

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

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

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