Đáp án:
`x \ in \ {11/12;-19/12}`
Giải thích các bước giải:
`21/16 - (x+1/3)^2 = -0,25`
`to (x+1/3)^2 = 21/16 - (-0,25)`
`to (x+1/3)^2 = 25/16`
`to` \(\left[ \begin{array}{l}x+\dfrac{1}{3}=\dfrac{5}{4}\\x+\dfrac{1}{3}=-\dfrac{5}{4}\end{array} \right.\) `to` \(\left[ \begin{array}{l}x=\dfrac{11}{12}\\x=-\dfrac{19}{12}\end{array} \right.\)
Vậy `x \ in \ {11/12;-19/12}`
