Question

    giúp mình với

Answer 1

2:

a: \(\dfrac{1}{3}+\dfrac{2}{3}:x=5\)

=>\(\dfrac{2}{3}:x=5-\dfrac{1}{3}=\dfrac{14}{3}\)

=>\(x=\dfrac{2}{3}:\dfrac{14}{3}=\dfrac{2}{3}\cdot\dfrac{3}{14}=\dfrac{2}{14}=\dfrac{1}{7}\)

b: \(\left(x+\dfrac{1}{2}\right)^2=16\)

=>\(\left[{}\begin{matrix}x+\dfrac{1}{2}=4\\x+\dfrac{1}{2}=-4\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{7}{2}\\x=-\dfrac{9}{2}\end{matrix}\right.\)

1:

a: \(-12:\left(\dfrac{3}{4}:\dfrac{-5}{6}\right)^2\)

\(=-12:\left(\dfrac{3}{4}\cdot\dfrac{-6}{5}\right)^2\)

\(=-12\cdot\left(\dfrac{9}{10}\right)^2=-12\cdot\dfrac{81}{100}=-\dfrac{243}{25}\)

b: \(\left|-\dfrac{1}{2}\right|+\left(-\dfrac{1}{3}\right)^2\cdot\left|-2\right|-\left(-\dfrac{2}{3}\right)^0\)

\(=\dfrac{1}{2}+\dfrac{1}{9}\cdot2-1\)

\(=\dfrac{2}{9}-\dfrac{1}{2}=\dfrac{4-9}{18}=-\dfrac{5}{18}\)