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.
Answer:
or 
Step-by-step explanation:
we know that
Applying Pythagoras' Theorem, calculate how many kilometers eastward Santos walked
so
Let
x----> quantity of kilometers eastward that Santos walked
----> exact value
-----> approximate value
Answer:
Step-by-step explanation:
Answer:
First step of the problem
Step-by-step explanation:
The mistake that Carly did while solving the equation was that she multiplied -4 with 10, when there was no reason to. If she had to, it would be if -4 was 1 over -4 and then to get rid of that should would multiplied that on both sides. Both in this case there was no reason to.
Besides that, the real way to solve the problem is by doing these steps.
1. Distribute property
-4(7j+2) = 10 => take -4 times 7j and -4 times POSITIVE 2
-28j-8= 10
You may be wondering why can't we add 7j and 2 together? Well it's because they aren't the same variable if 7j was just 7, then you could add 7 and 2 together. And if 2 was 2j, you would add 7j and 2j together. This type of process is called "combine like terms." It's when you add or subtract all the terms that are the same variable.
2. Get "j" on one side
-28j-8= 10
<u> +8 +8 </u>
-28j= 18
With this we had to add 8 on both sides to get -28j on one side of the equation. This is how we ended up with -28j= 18
3. Get "j" all alone
<u>-28j= 18 </u>
18
j= -28/18
or j= -14/9
Why did we divide 18? Well if you divide 18 on both sides, you have one side cancel out and the other side resulting in the coefficient with the variable divided by the number, this will cause "j" to be alone or have an answer.
The right answer for "j" is actually -14/9
I hope this help you understand, if not don't be afraid to ask questions or even comment. Hope you have a great day, bye! :D
