Answer:
k = 7
Step-by-step explanation:
Step 1: Write equation
-18 = 5 - (6k - 19)
Step 2: Solve for <em>k</em>
<u>Distribute negative:</u> -18 = 5 - 6k + 19
<u>Combine like terms:</u> -18 = -6k + 24
<u>Subtract 24 on both sides:</u> -42 = -6k
<u>Divide both sides by -6:</u> k = 7
Step 3: Check
<em>Plug in k to verify it's a solution.</em>
-18 = 5 - (6(7) - 19)
-18 = 5 - (42 - 19)
-18 = 5 - 23
-18 = -18
Answer:
The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.
The function to represent the mass of the sample after t days is 
Step-by-step explanation:
Exponential equation of decay:
The exponential equation for the amount of a substance is given by:

In which A(0) is the initial amount and r is the decay rate, as a decimal.
Hourly rate of change:
Decreases 26% by day. A day has 24 hours. This means that
; We use this to find r.



![\sqrt[24]{(1-r)^{24}} = \sqrt[24]{0.74}](https://tex.z-dn.net/?f=%5Csqrt%5B24%5D%7B%281-r%29%5E%7B24%7D%7D%20%3D%20%5Csqrt%5B24%5D%7B0.74%7D)



The hourly decay rate is of 1.25%, so the hourly rate of change is of -1.25%.
Starts out with 810 grams of Element X
This means that 
Element X is a radioactive isotope such that its mass decreases by 26% every day.
This means that we use, for this equation, r = 0.26.
The equation is:



The function to represent the mass of the sample after t days is 
Lights flash every four seconds. the store owner turns on the lights. After how many seconds Will all three lights flash at the same time for the first ...
Option C: There are no solutions
Explanation:
The linear equations is graphed.
We need to determine the solution of the system of equations.
The solution of the equations can be determined by finding the point of intersection of the two equations.
From the figure, it is obvious that the two equations are parallel to each other.
Also, the parallel lines have the same slope and the parallel lines never intersect.
Hence, the system consisting of parallel lines have no solution.
Therefore, the solution to the system of linear equations graphed is no solution.
Thus, Option C is the correct answer.
To work out the distance of the path, you need to find out the circumference.
Formula for circumference = pi multiplied by the diameter
So you simply do:
pi multiplied by 1.4 miles
And you should get:
4.39822971503... miles
Simply round the result to an appropriate value (e.g. 3 decimal places).
Answer: 4.398 miles (to 3dp)
Hope the answer helps :)