Tìm x , biết: e) 3/ 4 − ( x + 1/ 2 ) ^2 = 11 /16 ;

e) \(\frac{3}{4} - {\left( {x + \frac{1}{2}} \right)^2} = \frac{{11}}{{16}}\)

\({\left( {x + \frac{1}{2}} \right)^2} = \frac{3}{4} - \frac{{11}}{{16}}\)

\({\left( {x + \frac{1}{2}} \right)^2} = \frac{1}{{16}}\)

\({\left( {x + \frac{1}{2}} \right)^2} = {\left( {\frac{1}{4}} \right)^2}\)   hoặc    \({\left( {x + \frac{1}{2}} \right)^2} = {\left( { - \frac{1}{4}} \right)^2}\)

\(x + \frac{1}{2} = \frac{1}{4}\)                           \(x + \frac{1}{2} = - \frac{1}{4}\)

\(x = \frac{1}{4} - \frac{1}{2}\)                         \(x = - \frac{1}{4} - \frac{1}{2}\)

\(x = \frac{{ - 1}}{4}\).                                 \(x = \frac{{ - 3}}{4}\).

Vậy \(x \in \left\{ {\frac{{ - 1}}{4}\;;\;\frac{{ - 3}}{4}} \right\}\)