Answer: She started with $160.
It will take 6 weeks before she has less than half of what she originally invested.
Step-by-step explanation:
If her money is decreasing in value by 11% each week, it means that the rate at which it is decreasing is exponential.
We would apply the formula for exponential decay which is expressed as
A = P(1 - r)^t
Where
A represents the value of the investment after t weeks.
t represents the number of weeks.
P represents the initial value of the investment.
r represents rate of depreciation.
From the information given,
A = $142.40
r = 11% = 11/100 = 0.11
t = 1
Therefore
142.40 = P(1 - 0.11)^1
142.40 = P(0.89)
P = 142.4/0.89
P = 160
For her to have half of what she invested originally, then
80 = 160(0.89)^t
80/160 = (0.89)^t
0.5 = (0.89)^t
Taking log of both sides to base 10
Log 0.5 = log0.89^t = tlog0.89
- 0.3010 = - 0.051t
t = - 0.3010/- 0.051
t = 5.9
Approximately 6 weeks
Answer:
No, it's not a solution.
Step-by-step explanation:
-2 + 4(3) = 4
-2 + 12 = 10
-2 + 3(3) = 1
-2 + 9 = 7
To do this problem, you need to use a process called completing the square. Let me explain:
To complete the square on the function f(x) = x² + 8x +13, first group the first two terms in ( ) and leave some space at the end as follows:
f(x) = (x² + 8x ) + 13 Now our next step is to fill in the space and adjust our expression on the right hand side of the function. To do this, we take half of the middle number 8 and then square it: so 4² = 16 and we fill in our space inside the ( ) with this value 16;
f(x) = (x² + 8x + 16) + 13 now what we have done is to increase the overall value of our expression on the right by 16, but we want the overall value to remain the same. To fix this we simply need to subtract 16 at the end like this: f(x) = (x² + 8x + 16) + 13 -16 we can simplify and get the following.
f(x) = (x² + 8x + 16) - 3 At this point we're almost done.. All we need to do now is to rewrite the what is in the parentheses in a slightly different form. Here is what it will look like: f(x) = (x + 4)² - 3 notice all I did was take the sum of the square root of x² and the square root of 16 originally in the ( ) to get then new expression inside the ( ) and then square that ( )²
Now this is a nice form to have because you can get the vertex straight from this form.. IN FACT this is called vertex form or (h,k) form for short. In general the form is f(x) = a(x - h)² + k don't worry about the 'a' for now.. you might see that in our case it is just 1 and will not effect our equation. You only have to consider this if the original leading coefficient of the quadratic is not 1 to begin with...
So you can see that our vertex is (-4,-3)
Hope this is helpful, but if you have questions let me know.
Answer:
Step-by-step explanation:
We know (Ohm second law) that 
where k inlcudes the rest of the parameters (material, lenght). In our situation we have k= 
. The moment the diameter becomes 8mm R becomes
The athlete's average speed was 300 meters/minute.
<h3>How to calculate the speed of the athlete?</h3>
To calculate the speed of the athlete we must perform the following operations.
Divide the distance into the total time:
Transform the value from seconds to minutes, for which we must multiply 5 by 60 because each minute is made up of 60 seconds.
- 5m/sec × 60sec = 300m/min
According to the above, the average speed of the athlete is 300m/min.
Learn more about speed in: brainly.com/question/7359669
