Question

[Nguyễn Duy]

4,Tìm x biết

a,\(\frac{-2}{3}\cdot x+\frac{1}{5}=\frac{3}{10}\)

b,\(\frac{2}{3}\cdot x-\frac{3}{2}\cdot x=\frac{5}{12}\)

c,\(\left(4,5-2x\right)\cdot\left(-1\frac{4}{7}\right)=\frac{11}{14}\)

d,\(\frac{1}{4}+\frac{1}{3}:3x=-5\)

e,\(\left(2\frac{4}{5}x-50\right):\frac{2}{3}=51\)

g,\(|4x-1|=\left(-3^2\right)\)

h,\(|x+70|=2\frac{1}{5}\)

i,\(\left(x-1^3\right)=125\)

k,\(\left(x+\frac{1}{2}\right)\cdot\left(\frac{2}{3}-2x\right)=0\)

Giúp mình nhé!!!

Answer 1

[Phùng Tuệ Minh]

4a) \(\frac{-2}{3}x=\frac{3}{10}-\frac{1}{5}=\frac{1}{10}\)

\(\Leftrightarrow x=\frac{1}{10}:\frac{-2}{3}=\frac{1}{10}.\frac{3}{-2}=\frac{3}{-20}\)

Vậy x=\(\frac{3}{-20}\)

b) \(\frac{2}{3}x-\frac{3}{2}x=\frac{5}{12}\)

\(\Leftrightarrow\left(\frac{2}{3}-\frac{3}{2}\right)x=\frac{5}{12}\)

\(\Leftrightarrow\frac{-5}{6}x=\frac{5}{12}\)

\(\Leftrightarrow x=\frac{5}{12}:\frac{-5}{6}=\frac{5}{12}.\frac{6}{-5}=\frac{1}{-2}\)

Vậy x=\(\frac{1}{-2}\)

g)Sửa đề: \(\left|4x-1\right|=\left(-3\right)^2\)

\(\Leftrightarrow\left|4x-1\right|=9\)

\(\Rightarrow\left[{}\begin{matrix}4x-1=9\\4x-1=\left(-9\right)\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{5}{2}\\x=-2\end{matrix}\right.\)

Vậy \(x\in\left\{\frac{5}{2};-2\right\}\)

i) \(\left(x-1^3\right)=125\)

\(\Leftrightarrow x-1=125\)

\(\Leftrightarrow x=125+1=126\)

Vậy x=126

k) \(\left(x+\frac{1}{2}\right).\left(\frac{2}{3}-2x\right)=0\)

\(\Rightarrow\left[{}\begin{matrix}x+\frac{1}{2}=0\\\frac{2}{3}-2x=0\end{matrix}\right.\)

\(\Leftrightarrow\left[{}\begin{matrix}x=\frac{-1}{2}\\x=\frac{1}{3}\end{matrix}\right.\)

Vậy \(x\in\left\{\frac{-1}{2};\frac{1}{3}\right\}\)

Answer 2

[Nguyễn Duy]

xin lỗi câu h tui xin chữa lại là:\(|x+70\%|=2\frac{1}{5}\)