Question

Giúp mk với ạ

Answer 1

1) Ta có: \(x+\dfrac{1}{5}=0.25\)

\(\Leftrightarrow x=\dfrac{1}{4}-\dfrac{1}{5}\)

hay \(x=\dfrac{1}{20}\)

Vậy: \(x=\dfrac{1}{20}\)

2) Ta có: \(\dfrac{2}{7}-\dfrac{3}{7}:x=\dfrac{1}{5}\)

\(\Leftrightarrow\dfrac{3}{7}:x=\dfrac{2}{7}-\dfrac{1}{5}=\dfrac{3}{35}\)

hay x=5

Vậy: x=5

3) Ta có: \(\left(3x-1.5\right)\left(-\dfrac{1}{2}x+5\right)=0\)

\(\Leftrightarrow\left[{}\begin{matrix}3x-1.5=0\\-\dfrac{1}{2}x+5=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{2}\\x=10\end{matrix}\right.\)

Vậy: \(x\in\left\{\dfrac{1}{2};10\right\}\)

4) Ta có: \(\left(x+3\right)^2-\dfrac{1}{3}=\dfrac{1}{9}\)

\(\Leftrightarrow\left(x+3\right)^2=\dfrac{4}{9}\)

\(\Leftrightarrow\left[{}\begin{matrix}x+3=\dfrac{2}{3}\\x+3=-\dfrac{2}{3}\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{7}{3}\\x=-\dfrac{9}{3}\end{matrix}\right.\)

Vậy: \(x\in\left\{-\dfrac{7}{3};-\dfrac{9}{3}\right\}\)

5) Ta có: \(60\%x-x+\dfrac{1}{3}=2\)

\(\Leftrightarrow\dfrac{-2}{5}x=\dfrac{5}{3}\)

hay \(x=-\dfrac{25}{6}\)

Vậy: \(x=-\dfrac{25}{6}\)