1.
\(a.\left(1-\dfrac{2}{7}\right)^2-\left|-\dfrac{4}{7}+\left(-\dfrac{9}{14}\right)\right|=\left(\dfrac{5}{7}\right)^2-\left|-\dfrac{17}{14}\right|=\dfrac{25}{49}-\dfrac{17}{14}=\dfrac{-69}{98}.\)
\(b.\left(-\dfrac{1}{3}\right)^2-\dfrac{1}{6}\sqrt{16}:\left(0,75\right)=\dfrac{1}{9}-\dfrac{1}{6}.4:\dfrac{3}{4}=\dfrac{1}{9}-\dfrac{8}{9}=-\dfrac{7}{9}.\)
2.
\(a.14,2-\left(\dfrac{2}{5}-x\right)=2,6.\Leftrightarrow\dfrac{2}{5}-x=11,6.\Leftrightarrow x=-11,2.\)
\(b.\left|x-\dfrac{1}{4}\right|=\dfrac{3}{8}.\Leftrightarrow\left[{}\begin{matrix}x-\dfrac{1}{4}=\dfrac{3}{8}.\\x-\dfrac{1}{4}=\dfrac{-3}{8}.\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=\dfrac{1}{8}.\\x=-\dfrac{1}{8}.\end{matrix}\right.\)
