Answer:
there is an economic principle that states that 1 dollar today is worth more than 1 dollar in the future, since an invested dollar could earn interests and gain value.
For example, we can assume a 6% interest rate (0.5% monthly interest rate), and using the present value formula we can determine the present value of $100:
- given to us in 30 days = $100 / (1 + 0.5%)¹ = $99.50
- given to us in 150 days = $100 / (1 + 0.5%)⁵ = $97.54
- given to us in 300 days = $100 / (1 + 0.5%)¹⁰ = $95.13
In order to calculate the value of $100 given to us tomorrow, we would need to determine a daily interest rate = 6% / 360 = 0.00017
- $100 given to us tomorrow = $100 / (1 + 0.00017)¹ = $99.98
since the amount of money is not that large and the interest rate is rather low, the difference in value is not that large. But imagine if you used a 24% interest rate instead of 6% (monthly interest rate = 2%)
- $100 given to us in 30 days = $100 / (1 + 2%)¹ = $98.04
- $100 given to us in 150 days = $100 / (1 + 2%)⁵ = $90.57
- $100 given to us in 300 days = $100 / (1 + 2%)¹⁰ = $82.03
as the interest rate increases, the present value decreases.
So to solve this you need to reverse factor this problem
x^2 + 8x + 7 = 0
The common formula is this for factoring ax^2 + bx + c
Now you have to think what multplties to "c" and adds up to "b".
So in this case it's 7 x 1 = 7 and 7 + 1 = 8
So you set it up like this
(x + 7)(x + 1) = 0
So now you can check the factors by multiplying them together and see if it gets your original equation which is does.
So finally to get the answers you need to set each parenthesis to 0 and solve for x.
x + 7 = 0
x + 1 = 0
and we get x = -1 and - 7
You can also plug these two answers back into your original equation to see if it equals 0.
If you have any questions please feel free to comment
Step-by-step explanation:
a 9/2 is the correct answer.
Answer:
<h3>y = 56x</h3>
Step-by-step explanation:
Given the amount to keep one adult in a day to be x
Since 7 days = 1 week
Amount it will take to keep one adult for a week will be 7x
one adult = 7x pounds
To get the expression that show how much it costs per week to keep the 8 adults, we will say;
8 adults = y pounds
where y is the required amount
Solving both expressions
one adult = 7x pounds
8 adults = y pounds
Cross multiply
1 * y = 7x * 8
y = 56x
Hence the required expression is y = 56x
