Giải các phương trình sau:a) \(\sqrt {4{x^2}}  = 6\)b) \(\sqrt {{x^2}}  = \left| { - 8} \right|\) c) \(\sqrt {{x^2} - 22x + 121}  = 2x - 15\)d) \(\sqrt {1 + 9{x^2} - 6x}  = 2x + 6\...

A \(\begin{array}{l}
a)\,\,\,S = \left\{ { - 3;\,\,3} \right\}\\
b)\,\,S = \left\{ {8} \right\}\\
c)\,\,S = \left\{ {\frac{{26}}{3}} \right\}\\
d)\,\,S = \left\{ { - 1;\,\,7} \right\}
\end{array}\)

B \(\begin{array}{l}
a)\,\,\,S = \left\{ { - 3;\,\,3} \right\}\\
b)\,\,S = \left\{ {8;\,\, - 8} \right\}\\
c)\,\,S = \left\{ {-\frac{{26}}{3}} \right\}\\
d)\,\,S = \left\{ { - 1;\,\,7} \right\}
\end{array}\)

C \(\begin{array}{l}
a)\,\,\,S = \left\{ { - 3;\,\,3} \right\}\\
b)\,\,S = \left\{ {8;\,\, - 8} \right\}\\
c)\,\,S = \left\{ {\frac{{26}}{3}} \right\}\\
d)\,\,S = \left\{ { - 1;\,\,7} \right\}
\end{array}\)

D \(\begin{array}{l}
a)\,\,\,S = \left\{ {3} \right\}\\
b)\,\,S = \left\{ {8;\,\, - 8} \right\}\\
c)\,\,S = \left\{ {\frac{{26}}{3}} \right\}\\
d)\,\,S = \left\{ { - 1;\,\,7} \right\}
\end{array}\)