10(x^2) = 80x
(divide by the 10)
x^2 = 8x
which also equals
(x)(x) = 8x
(divide by x)
x = 8
To find (fg)(x), you must mult. together the two binomial functions f and g:
(fg)(x) = (6-5x)(6x^2+x = 36x^2 + 6x - 30x^3 - 5x^2
and then you must combine like terms: (fg)(x) = -30x^3 + 31x^2 + 6x
Answer:
Correct answer is option d. increase of $1 in advertising is associated with an increase of $4000 in sales.
Step-by-step explanation:
Given the equation of regression analysis is given as:

where
is the cost on advertising in Dollars.
and
is the sales in Thousand Dollars.
To find:
The correct increase in sales when there is increase in the advertising cost.
Solution:
Suppose there is an increase of
in the advertising cost.
Let the initial cost be
then the cost will be
.
Initial sales
....... (1)
After increase of $1 in advertising cost, final cost:

Subtracting (2) from (1) to find the increase in the sales:

The units of sales is Thousand Dollars ($1000).
So, increase in sales = 
So, correct answer is:
d. increase of $1 in advertising is associated with an increase of $4000 in sales.
The answer that I would say is best: B.) 2+2i
Hope This Helps....... Have A Nice Daaay !