` a) ` ` 2/3 - (3/4 - x) = \sqrt{\frac{1}{9}} `
` <=> 2/3 - 3/4 + x - 1/3 = 0 `
` <=> x - 3/4 + 1/3 = 0 `
` <=> x = 5/(12) `
Vậy ` x = 5/(12) `
` b) ` ` (1/2 - x)^2 = (-2)^2 `
` <=> ` \(\left[ \begin{array}{l}\frac{1}{2}-x=2\\\frac{1}{2}x=-2\end{array} \right.\)
` <=> ` \(\left[ \begin{array}{l}x=\frac{-3}{2}\\x=\frac{5}{2}\end{array} \right.\)
Vậy ` x = \frac{-3}{2} ` hoặc ` x = 5/2 `
