Answer:
2) -81t² +16
Step-by-step explanation:
(9t -4)(-9t -4) = (9t x -9t) + (9t x -4) + (-4 x -9t) + (-4 x -4)
= -81t² - 36t + 36t + 16
= -81t² + 16
Given:
- Bought n items of product A at 1/5 rs each
- bought n items of product B at 1/4 rs each
He mixed the two items and sold each at 2/9 rs each.
He lost 3 rs in the above batch of articles.
Solution:
revenue = 2n* (2/9) rs = 4n/9 rs
cost = n/5+n/4 rs = n(1/5+1/4)
Profit = revenue-cost = 4n/9-n(1/5+1/4) = -3 rs
Solve for n
4n/9-n(1/5+1/4) = -3
factor out n
n(4/9-1/5-1/4)=-3
n(80-36-45)/180=-3
-n/180=-3
n=3*180=540
Total number of products bought
= n+n = 540+540 = 1080
Answer: a) c(x) = 0.124x + 1.1, b) 13 units
Step-by-step explanation: Revenue function = R(x) = 0.21x
Profit function = p(x) = 0.086 - 1.1
Cost function = c(x) =?
A)
Recall that profit = total revenue - total cost
Hence, total cost = total revenue - profit
c(x) = 0.21x - (0.086x - 1.1)
c(x) = 0.21x - 0.086x + 1.1
c(x) = 0.124x + 1.1
B)
Break even point is the point where total revenue equals total cost
R(x) = c(x)
0.21x = 0.124x + 1.1
0.21x - 0.124x = 1.1
0.086x = 1.1
x = 1.1/0.086
x = 12.79 which is approximately 13 units
Given:
The increase in pressure P is the linear function of the depth d.

The cost of dinner is $300 and $10 per students.
To find:
The initial value and rate of change and their interpretation.
Find the cost function C where n is the number of students.
Solution:
The slope intercept form of a linear function is
...(i)
where, m is rate of change and b is y-intercept or initial value.
We have,
...(ii)
From (i) and (ii), we get

The initial value is 14.7. It means, the pressure at sea level is 14.7 pounds psi.
Rate of change is 0.445. It means, the pressure is increasing by 0.445 pounds psi for every feet.
The cost of dinner is $300 and $10 per students.
Let C(n) be the total cost for dinner and n be the number of students.
Fixed cost = $300
Additional cost for 1 student = $10
Additional cost for n student = $10n
Now,
Total cost = Fixed cost + Additional cost

Therefore, the required cost function is
.
81 , 243 , 729 the pattern is mutiply each by three