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A \(2\sqrt 2 \)

B \(\sqrt 2 \)

C \({{\sqrt 2 } \over 2}\)

D 2

A 7

B 5

C 3

D 1

A \({5 \over 2}\)

B \(2\sqrt 2 \)

C 2

D 3

A \({1 \over 2}\)

B \({1 \over 3}\)

C 1

D 2

A 1

B 2

C 3

D 4

A 1

B 2

C 3

D \(2\sqrt 2 \)

A \(a + b = 4\)

B \(a + b < 4\)

C \(a + b > 4\)

D \(a + b \le 4\)

A \(x + y \ge 12\)

B \(x + y \ge 72\)

C \(144 \le {x^2} + {y^2}\)

D \(72 < {x^2} + {y^2}\)

A \(\sqrt {xy}  \le 6\)

B \(6 \ge xy\)

C \(xy < 36\).

D \(\sqrt {xy}  \ge 6\)

A \(x + y \le \sqrt {2\left( {{x^2} + {y^2}} \right)} \)

B \(\sqrt {xy}  \le {{x + y} \over 2}\)

C \(xy \le {\left( {{{x + y} \over 2}} \right)^2}\)

D \(xy \le {{{x^2} + {y^2}} \over 2}\)

A \(x = 4\)           

B \(x = 3\)

C \(x = 5\)

D \(x = {5 \over 2}\)

A \({8 \over {729}}\)       

B \({8 \over {27}}\)

C \({1 \over 9}\)

D \({8 \over {29}}\)

A \({\rm{(ax}} + by)(bx + ay) \ge {(a + b)^2}xy\)

B \({\rm{(ax}} + by)(bx + ay) > {(a + b)^2}xy\)

C \({\rm{(ax}} + by)(bx + ay) \le {(a + b)^2}xy\)          

D \({\rm{(ax}} + by)(bx + ay) < {(a + b)^2}xy\)

A \(a\sqrt {b - 1}  + b\sqrt {a - 1}  \le ab\)

B \(a\sqrt {b - 1}  + b\sqrt {a - 1}  \le {1 \over 2}ab\)

C \(a\sqrt {b - 1}  + b\sqrt {a - 1}  \ge ab\)        

D \(a\sqrt {b - 1}  + b\sqrt {a - 1}  \ge {1 \over 2}ab\)

A 4

B 1

C 2

D 3

A \(3\sqrt 2 \)

B \(2\sqrt 3 \)

C \(3\sqrt 3 \)

D \(\sqrt 3 \)

A \({1 \over {2\sqrt 2 }}\)

B \(\sqrt 2 \)

C \({{\sqrt 2 } \over 2}\)

D \({1 \over 2}\)

A \(\sqrt {ab}  \le {{a + b} \over 2}\).

B \({2 \over {{1 \over a} + {1 \over b}}} < \sqrt {ab} \)

C \({{a + b} \over 2} < b\)          

D \({2 \over {{1 \over a} + {1 \over b}}} \ge {{a + b} \over 2}\)

A \({7 \over 2}\)

B \({5 \over 2}\)

C 1

D 2

A \(3\sqrt 7 \)

B 5

C 6

D 8