A.8
B.7
C.16
D.9

A.9cm
B.8cm.
C.6cm.
D.5cm

A.bằng cách li địa lí.
B.bằng cách li sinh thái.
C.bằng tự đa bội.
D.bằng lai xa và đa bội hoá.

A.
B.
C.
D.

A.\(\left( {x;y} \right) = \left( {4 + \sqrt {34} ;49 + 10\sqrt {34} } \right)\)
B.\(\left( {x;y} \right) = \left( {3 + \sqrt {34} ;49 + 8\sqrt {34} } \right)\)
C.\(\left( {x;y} \right) = \left( {3 + \sqrt {34} ;59 + 8\sqrt {34} } \right)\)
D.\(\left( {x;y} \right) = \left( {5 + \sqrt {34} ;59 + 10\sqrt {34} } \right)\)

A.\(S = \left\{ { - \dfrac{1}{2};2} \right\}\)
B.\(S = \left\{ {\dfrac{1}{2}; - 2} \right\}\)
C.\(S = \left\{ {\dfrac{1}{2};2} \right\}\)
D.\(S = \left\{ { - \dfrac{1}{2}; - 2} \right\}\)

A.
B.
C.
D.

A.
B.
C.
D.

A.\(\left( {2;1} \right);\left( { - 4;2} \right);\left( { - 14;33} \right);\left( {32;57} \right)\)
B.\(\left( { - 2;1} \right);\left( { - 4;2} \right);\left( { - 14;33} \right);\left( { - 32;57} \right)\)
C.\(\left( {2;1} \right);\left( { - 4;1} \right);\left( { - 14;33} \right);\left( { - 32;57} \right)\)
D.\(\left( { - 2;1} \right);\left( { - 4;1} \right);\left( { - 14;33} \right);\left( {32;57} \right)\)

A.\(S = \left\{ { \pm 2;\dfrac{{3 \pm \sqrt {19} }}{2}} \right\}\)
B.\(S = \left\{ {2;\dfrac{{3 + \sqrt {19} }}{2}} \right\}\)
C.\(S = \left\{ { \pm 2;\dfrac{{3 + \sqrt {19} }}{2}} \right\}\)
D.\(S = \left\{ {2;\dfrac{{3 \pm \sqrt {19} }}{2}} \right\}\)