A.\(12\pi {a^2}\)
B.\(36\pi {a^2}\)
C.\(14\pi {a^2}\)
D.\(15\pi {a^2}\)

A.\(\dfrac{1}{3}\)
B.\(\dfrac{1}{2}\)
C.2
D.3

A.\(y' = {2.4^{2x}}.\ln 2\)
B.\(y' = {4^{2x}}\ln 4.\)
C.\(y' = {4^{2x}}\ln 2.\)
D.\(y' = {2.4^{2x}}\ln 4.\)

A.\(C_5^2\)
B.\(C_4^2\)
C.\(A_5^2\)
D.\(A_4^2\)

A.\(\overrightarrow a  = \left( {1;2; - 3} \right),\) \(\overrightarrow b  = \left( {0; - 3;4} \right),\) \(\overrightarrow c  = \left( { - 1; - 2;0} \right)\)
B.\(\overrightarrow a  = \left( {1;2;3} \right),\) \(\overrightarrow b  = \left( {0;3;4} \right),\) \(\overrightarrow c  = \left( { - 1; - 2;0} \right)\)
C.\(\overrightarrow a  = \left( {1;2;3} \right),\) \(\overrightarrow b  = \left( {0; - 3;4} \right),\) \(\overrightarrow c  = \left( { - 1;2;0} \right)\)
D.\(\overrightarrow a  = \left( {1;2; - 3} \right),\) \(\overrightarrow b  = \left( { - 3;4;0} \right),\) \(\overrightarrow c  = \left( { - 1;0; - 2} \right)\)

A.\(\left( { - 3;0} \right)\)
B.\(\left( { - 4;1} \right)\)
C.\(\left( { - \infty ; - 3} \right)\)
D.\(\left( {0; + \infty } \right)\)

A.\(y =  - 3x + 5\)
B.\(y =  - 3x + 1\)
C.\(y = 3x - 5\)
D.\(y =  - 3x - 1\)

A.CH3COOC2H5.
B.CH3COOCH=CH2.
C.CH3COOCH3.
D.(HCOO)2C2H4.

A.4,3 gam.
B.6,3 gam.
C.5,3 gam.
D.7,3 gam.

A.CH3COOC2H5.
B.HCOOC2H5.
C.CH3CH2COOCH3.
D.CH3COOCH3.