Question

Tìm x 

a) \(\left(\frac{-5}{3}\right)< x< \frac{-24}{35}.\left(\frac{-5}{6}\right)\)

b) \(\left(7x-11\right)^3=\left(-3\right)^2.15+208\)

Answer 1

\(x\inℤ\) hả 

Answer 2

x thuộc Z

Answer 3

CHỜ TÍ

Answer 4

a)\(\frac{-5}{3}< x< \frac{-24}{35}.-\frac{5}{6}\)

\(\Rightarrow\frac{-5}{3}< x< \frac{4}{7}\)

\(\Rightarrow\frac{-35}{21}< x< \frac{12}{21}\)

\(\Rightarrow x\in\left\{\frac{-34}{21};\frac{-33}{21};\frac{-32}{21};...;\frac{10}{21};\frac{11}{21};\frac{12}{21}\right\}\)

Mà \(x\inℤ\) nên \(x\in\left\{-1;0;1\right\}\)

Answer 5

\(a,\left[\frac{-5}{3}\right]< x< \frac{-24}{35}\cdot\left[\frac{-5}{6}\right]\)

\(\Rightarrow\frac{-5}{3}< x< \frac{-24\cdot(-5)}{35\cdot6}\)

\(\Rightarrow\frac{-5}{3}< x< \frac{-4\cdot(-1)}{7\cdot1}=\frac{4}{7}\)

\(\Rightarrow\frac{5}{3}< x< \frac{4}{7}\)

\(\Rightarrow\frac{35}{21}< x< \frac{12}{21}\)

Mà \(x\inℤ\)nên \(x\in\varnothing\)

Vậy không có giá trị x thỏa mãn

\(b,(7x-11)^3=(-3)^2\cdot15+208\)

\(\Rightarrow(7x-11)^3=9\cdot15+208\)

\(\Rightarrow(7x-11)^3=343\)

\(\Rightarrow(7x-11)^3=7^3\)

\(\Rightarrow7x-11=7\)

\(\Rightarrow7x=7+11\)

\(\Rightarrow7x=18\)

\(\Rightarrow x=\frac{18}{7}\)

=> x không có giá trị thỏa mãn vì \(x\inℤ\)

Answer 6

Lộn phần a dòng thứ 3,4,...

Mk sửa lại :

\(\frac{-5}{3}< x< \frac{4}{7}\)

\(\Rightarrow\frac{-35}{21}< x< \frac{12}{21}\)

\(\Rightarrow-35< x< 12\)

\(\Rightarrow x\in\left\{-34;-33;...;11\right\}\)

Answer 7

Tử Thần sai nha