Answer:
Simplifying
(2j + 1) * 9 + -7j = 0
Reorder the terms:
(1 + 2j) * 9 + -7j = 0
Reorder the terms for easier multiplication:
9(1 + 2j) + -7j = 0
(1 * 9 + 2j * 9) + -7j = 0
(9 + 18j) + -7j = 0
Combine like terms: 18j + -7j = 11j
9 + 11j = 0
Solving
9 + 11j = 0
Solving for variable 'j'.
Move all terms containing j to the left, all other terms to the right.
Add '-9' to each side of the equation.
9 + -9 + 11j = 0 + -9
Combine like terms: 9 + -9 = 0
0 + 11j = 0 + -9
11j = 0 + -9
Combine like terms: 0 + -9 = -9
11j = -9
Divide each side by '11'.
j = -0.8181818182
Simplifying
j = -0.8181818182
Answer:
<em>C(19)=12 responses</em>
Step-by-step explanation:
<u>Exponential Decay Function</u>
The exponential function is frequently used to model natural growing or decaying processes, where the change is proportional to the actual quantity.
An exponential decaying function can be expressed as follows:

Where:
C(t) is the actual value of the function at time t
Co is the initial value of C at t=0
r is the decaying rate, expressed in decimal
The company puts out an advertisement for a job opening. Initially, the company got 90 responses to the advertisement. Each day, the responses declined by 10%.
This is an example where the decay model can be used to calculate the responses to the advertisement at the day t.
The initial value is Co=90, the decaying rate is r=10% = 0.10. The model is written as:

Calculating:

We are required to calculate the number of responses at day t=19, thus:

C(19)=12 responses
C B A are the orders of the answers
Answer: c. f - 3 + 6d
Explanation: 5d - d + 4 + 2d - 5f - 6f - 7
- 5f - 6f = f
4 - 7 = -3
5d - d = 4d, 4d + 2d = 6d