\(x:(3\frac{1}{2}-5\frac{1}{6})=4\frac{1}{5}-6\frac{2}{3}\)                           b,\((2\frac{1}{3}+3\frac{1}{2})\cdot x=-4\frac{1}{4}+3\frac{1}{7}\)

\(x:\frac{-5}{3}\)=\(\frac{-37}{15}\)                                                              \(\frac{35}{6}\cdot x=\)\(\frac{-31}{28}\)

\(x=\frac{-37}{15}\cdot\frac{-5}{3}\)                                                              \(x=\frac{-31}{28}:\)\(\frac{35}{6}\)

\(x=\frac{37}{9}\)                                                                              \(x=\frac{-93}{490}\)

Vậy x=\(\frac{37}{9}\)                                                                           Vậy x=\(\frac{-93}{490}\)

7,5x:\((9-6\frac{13}{21})=2\frac{13}{25}\)

7,5x:\(\frac{50}{21}\)=\(\frac{63}{25}\)

7,5x=\(\frac{63}{25}:\frac{50}{21}=\frac{1323}{1250}\)

x=\(\frac{1323}{1250}:7,5\)

x=\(\frac{441}{3125}\)

Vậy x=\(\frac{441}{3125}\)

\(x\times\frac{6}{25}=\frac{15}{-13}\)

x=\(\frac{15}{-13}\div\frac{6}{25}\)

x=\(-\frac{125}{26}\)

các câu còn lại làm tương tự nha!!!

\(1.x.\frac{6}{25}=\frac{15}{-13}\\ x=\frac{15}{-13}:\frac{6}{25}\\ x=-\frac{125}{26}\)

\(2.x:\frac{4}{10}=\frac{13}{-45}+\frac{8}{15}\\ x:\frac{4}{10}=\frac{11}{45}\\ x=\frac{11}{45}.\frac{4}{10}\\ x=\frac{22}{225}\)

\(3.\frac{3}{8}-\frac{1}{6}.x=\frac{1}{4}\\ \frac{1}{6}.x=\frac{3}{8}-\frac{1}{4}\\ \frac{1}{6}.x=\frac{1}{8}\\ x=\frac{1}{8}:\frac{1}{6}\\ x=\frac{3}{4}\)

\(4.\frac{1}{3}+\frac{1}{2}:x=-4\\ \frac{1}{2}:x=-4-\frac{1}{3}=-\frac{13}{3}\\ x=\frac{1}{2}:\left(-\frac{13}{3}\right)=-\frac{3}{26}\)

\(5.x+\frac{7}{12}=\frac{17}{18}-\frac{1}{9}=\frac{5}{6}\\ x=\frac{5}{6}-\frac{7}{12}\\ x=\frac{1}{4}\)

\(1,\)\(x-\frac{3}{5}=\frac{3}{35}-\frac{-7}{6}\)

        \(x-\frac{3}{5}=\frac{3}{35}+\frac{7}{6}\)

        \(x-\frac{3}{5}=\frac{263}{210}\)

                    \(x=\frac{263}{210}+\frac{3}{5}\)

                    \(x=\frac{389}{210}\)

        VẬY: \(x=\frac{389}{210}\)

a)  \(2\frac{1}{4}x-9\frac{1}{4}=20\)

\(\frac{9}{4}x=20+\frac{37}{4}\)

\(\frac{9}{4}x=\frac{80}{4}+\frac{37}{4}\)

\(\frac{9}{4}x=\frac{117}{4}\)

\(x=\frac{117}{4}:\frac{9}{4}\)

\(x=\frac{117}{4}.\frac{4}{9}\)

\(x=13\)

Vậy x=13

a) \(2\frac{1}{4}x-9\frac{1}{4}=20\)

\(\Rightarrow\frac{9}{4}x-\frac{37}{4}=20\)

\(\Rightarrow\frac{9}{4}x=20+\frac{37}{4}\)

\(\Rightarrow\frac{9}{4}x=\frac{117}{4}\)

\(\Rightarrow x=\frac{117}{4}:\frac{9}{4}\)

\(\Rightarrow x=13\)

Vậy x = 13

b) \(0,25x-\frac{1}{5}x=\frac{13}{20}\)

\(\Rightarrow\left(0,25-\frac{1}{5}\right)x=\frac{13}{20}\)

\(\Rightarrow\frac{1}{20}x=\frac{13}{20}\)

\(\Rightarrow x=\frac{13}{20}:\frac{1}{20}\)

\(\Rightarrow x=13\)

Vậy x = 13

\(a,\)\(x+\frac{4}{5.9}+\frac{4}{9.13}+\frac{4}{13.17}+...+\frac{4}{41.45}=-\frac{37}{45}\)

  \(x+\left(\frac{9-5}{5.9}+\frac{13-9}{9.13}+\frac{17-13}{13.17}+...+\frac{45-41}{41.45}\right)=-\frac{37}{45}\)

  \(x+\left(\frac{1}{5}-\frac{1}{9}+\frac{1}{9}-\frac{1}{13}+\frac{1}{13}-\frac{1}{17}+....+\frac{1}{41}-\frac{1}{45}\right)-\frac{37}{45}\)

 \(x+\left(\frac{1}{5}-\frac{1}{45}\right)=-\frac{37}{45}\)

 \(x+\frac{8}{45}=-\frac{37}{45}\)

\(x=-\frac{37}{45}-\frac{8}{45}\)

\(x=-1\)

thế phần b, c đâu bạn

1. \(x=\frac{61}{42}\)

2. \(x=\frac{-36}{5}\) 

3. \(x=\frac{13}{11}\)

4. \(x=\frac{1}{12}\)

5.\(x=\frac{-5}{2}\)

(x²-1)²=9

=> x²-1 = 3 

x² = 3+1

x² = 4

=> x² = 4 = 2² ( x²=2² )

<=> x = 2

12:{390:[5.10²-(5³+x.7²)]} = 4

390:[5.10²-(5³+x.7²)] = 12:4

390:[5.10²-(5³+x.7²)] = 3

5.10²-(5³+x.7²) = 390 : 3

5.10²-(5³+x.7²) = 130

=> 500-(125+x+49)=130

125+x+49 = 500-130

125+x+49 = 370

125+x = 370-49

125+x = 321

x = 321-125

x = 106

5³(3x+2):13=10³:(13⁵:13⁴)

5³(3x+2):13=10³:13

5³(3x+2):13= 1000/13

125(3x+2):13 = 1000/13

125(3x+2) = 1000/13 . 13

125(3x+2) = 1000

3x+2 = 1000:125

3x+2 = 8

3x = 8-2

3x = 6

x = 6:3

x = 2