For the given vectors
and 
The dot product of vectors a and b is defined as = 
So, 

= -16+12
= -4
Answer: 3 • ? = -6
Reasoning: -6/ 3 = -2
3 • -2 = -6
Answer:
Only one extreme value of f(x) is possible.
Step-by-step explanation:
We are given the quadratic function of independent variable x which is f(x) = x² - 7x - 6 ......(1)
Now. the condition for extreme values of f(x) is 
Hence, differentiating both sides of equation (1) with respect to x, we get
= 0
⇒ x = 3.5.
So there is only one value of x for which f(x) has extreme value which is x = 3.5.
Therefore, only one extreme value of the given function is possible. (Answer)
Given:
second term = 18
fifth term = 144
The nth term of a geometric sequence is:

Hence, we have:

Divide the expression for the fifth term by the expression for the second term:

Substituting the value of r into any of the expression:

Hence, the explicit rule for the sequence is:
36v - 12 = 12 .....add 12 to both sides
36v - 12 + 12 = 12 + 12...simplify
36v = 24...divide both sides by 36
(36/36)v = 24/36
v = 2/3 <===