A.\(x =  2\).
B.\(x =  -2\).
C.\(x =  - 4\).
D.\(x =  4\).

A.\(x \in \left\{ { 0;\,\,1} \right\}\).
B.\(x \in \left\{ { - 1;\,\,1} \right\}\).
C.\(x \in \left\{ { - 1;\,\,0} \right\}\).
D.\(x \in \left\{ { 0} \right\}\).

A.\(x \in \left\{ {\sqrt {\frac{5}{4}}  - \frac{1}{4};\,\, - \sqrt {\frac{5}{4}}  - \frac{1}{4}} \right\}\).
B.\(x \in \left\{ {\sqrt {\frac{5}{4}}  - \frac{1}{4};\,\, - \sqrt {\frac{5}{4}}  + \frac{1}{4}} \right\}\).
C.\(x \in \left\{ {\sqrt {\frac{5}{2}}  - \frac{1}{4};\,\, - \sqrt {\frac{5}{2}}  - \frac{1}{4}} \right\}\).
D.\(x \in \left\{ {-\sqrt {\frac{5}{4}}  - \frac{1}{4};\,\, - \sqrt {\frac{5}{4}}  +\frac{1}{4}} \right\}\).

A.\(x \in \left\{ {\sqrt {\frac{5}{4}}  - \frac{1}{4};\,\, - \sqrt {\frac{5}{4}}  - \frac{1}{4}} \right\}\).
B.\(x \in \left\{ {\sqrt {\frac{5}{4}}  - \frac{1}{4};\,\, - \sqrt {\frac{5}{4}}  + \frac{1}{4}} \right\}\).
C.\(x \in \left\{ {\sqrt {\frac{5}{2}}  - \frac{1}{4};\,\, - \sqrt {\frac{5}{2}}  - \frac{1}{4}} \right\}\).
D.\(x \in \left\{ {-\sqrt {\frac{5}{4}}  - \frac{1}{4};\,\, - \sqrt {\frac{5}{4}}  +\frac{1}{4}} \right\}\).

A.\(864\,\,\left( {c{m^3}} \right)\)
B.\(846\,\,\left( {c{m^3}} \right)\)
C.\(684\,\,\left( {c{m^3}} \right)\)
D.\(648\,\,\left( {c{m^3}} \right)\)

A.\(2\) lần
B.\(3\) lần
C.\(\sqrt 2 \) lần
D.\(\sqrt 3 \) lần

A.\({I^2}r\).
B.\(\xi I\).
C.\({I^2}R\).
D.\({I^2}\xi \).

A.57,74.
B.59,07.
C.55,76.
D.31,77.

A.4
B.3
C.5
D.2

A.nilon-6; amilopectin; polistiren.
B.nilon-6,6; tơ axetat; amilozơ.
C.xenlulozơ; poli(vinyl clorua); nilon-7.
D.tơ visco; nilon-6; polietilen.