Answer:
The exact answer in terms of radicals is ![x = 5*\sqrt[3]{25}](https://tex.z-dn.net/?f=x%20%3D%205%2A%5Csqrt%5B3%5D%7B25%7D)
The approximate answer is 
(accurate to 5 decimal places)
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Work Shown:
Let ![y = \sqrt[5]{x^3}](https://tex.z-dn.net/?f=y%20%3D%20%5Csqrt%5B5%5D%7Bx%5E3%7D)
So the equation reduces to -7 = 8-3y
Let's solve for y
-7 = 8-3y
8-3y = -7
-3y = -7-8 ... subtract 8 from both sides
-3y = -15
y = -15/(-3) ... divide both sides by -3
y = 5
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Since and y = 5, this means we can equate the two expressions and solve for x
![\sqrt[5]{x^3} = 5](https://tex.z-dn.net/?f=%5Csqrt%5B5%5D%7Bx%5E3%7D%20%3D%205)
Raise both sides to the 5th power
![x = \sqrt[3]{3125}](https://tex.z-dn.net/?f=x%20%3D%20%5Csqrt%5B3%5D%7B3125%7D)
Apply cube root to both sides
![x = \sqrt[3]{125*25}](https://tex.z-dn.net/?f=x%20%3D%20%5Csqrt%5B3%5D%7B125%2A25%7D)
![x = \sqrt[3]{125}*\sqrt[3]{25}](https://tex.z-dn.net/?f=x%20%3D%20%5Csqrt%5B3%5D%7B125%7D%2A%5Csqrt%5B3%5D%7B25%7D)
![x = \sqrt[3]{5^3}*\sqrt[3]{25}](https://tex.z-dn.net/?f=x%20%3D%20%5Csqrt%5B3%5D%7B5%5E3%7D%2A%5Csqrt%5B3%5D%7B25%7D)
In a positive integers there are twenty whole numbers I hope this help
Answer:
B
Step-by-step explanation:
The given formula is f(x) = 20(1.2)^x
The formula is the starting amount multiplied by 1 + the percentage raised to the number of weeks.
A) the percent increase is 20% ( 1.2 in the formula is 1 +20% as a decimal)
B) the original amount is $20
C) for 2 weeks, replace x with 2 and solve:
20(1.2)^2
20(1.44) = $28.80
After 2 weeks the coupon is $28.80
D) To solve for the number of weeks (x) set the equation equal to $100:
100 = 20(1.2)^x
Divide both sides by 20:
5 = 1.2^x
Take the natural logarithm of both sides:
ln(5) = ln(1.2^x)
Use the logarithm rule to remove the exponent:
ln(5) = x ln(1.2)
Divide both sides by ln(1.2)
x = ln(5) / ln(1.2)
Divide:
X = 8.83
At 8.83 weeks the coupon would be $100, so after 9 weeks the coupon would be greater than $100
The answer is 9 weeks.
