A.4 mặt phẳng.  
B.3 mặt phẳng.  
C.6 mặt phẳng.
D.9 mặt phẳng.

A.\(S = ( - \infty ;2] \cup {\rm{[}}16; + \infty )\).
B.\(S = {\rm{[}}2;16]\)
C.\(S = (0;2] \cup {\rm{[}}16; + \infty )\). 
D.\(S = ( - \infty ;1] \cup {\rm{[}}4; + \infty )\).

A.\(D = \mathbb{R}\backslash {\rm{\{ }} - 2\} \) 
B.\(D = ( - \infty ; - 2) \cup {\rm{[}}3; + \infty )\)
C.\(D = ( - 2;3)\). 
D.\(D = ( - \infty ; - 2) \cup (3; + \infty )\)

A.\(P = 9{\log _a}b\).
B.\(P = 27{\log _a}b\).
C.\(P = 15{\log _a}b\)
D.\(P = 6{\log _a}b\)

A.\(V = \pi  - 1\)
B.\(V = (\pi  - 1)\pi \)
C.\(V = (\pi  + 1)\pi \)
D.\(V = \pi  + 1\)

A.\((0; + \infty )\)
B.\(( - 1;1)\)
C.\(( - \infty ; + \infty )\)
D.\(( - \infty ;0)\)

A.2
B.3
C.1
D.0

A.\(V = 128\pi \)
B.\(V = 64\sqrt 2 \pi \)
C.\(V = 32\pi \)
D.\(V = 32\sqrt 2 \pi \)

A.\(\vec i = (1;0;0)\)
B.\(\vec k(0;0;1)\)
C.\(\vec j(0;1;0)\)
D.\(\vec m = (1;1;1)\)

A.\(Q(2; - 1;5)\)
B.\(P(0;0; - 5)\)
C.\(N( - 5;0;0)\)
D.\(M(1;1;6)\)