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
To answer this item, we assume that the topic is in similar polygons such that the ratio of the corresponding sides should be equal. In this item,
BY/YC = AX/XC
Substituting the known values,
6/10 = 18/XC
The value of XC from the equation is 30. The answer is letter C.
Answer:
-4,3.5
Step-by-step explanation:
1st one
x-2x-20 = 12
-x = 32
x=-4
2nd one
-15=15q-50 - 5q
35= 10q
q = 3.5
This is the best I got Require to make 2 equations with the same repeating part and subtract them to eliminate the repeating part.
begin by letting x = 0.5555555................. (1)
To obtain the same repeating part after the decimal point need to multiply by 10
hence 10x = 5.555555........................(2)
It is important to obtain 2 equations in x, where the recurring part after the decimal points are exactly the same.
now subtract (1) from (2) to obtain fraction
(2) - (1) : <span>9x=5⇒x=<span><span>59</span></span></span>
