Answer:
(1/2,-5/2)
Step-by-step explanation:
Answer: Choice D
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Explanation:
The left portion is the interval (-∞, -2)
This is a shorthand way of saying
The curved parenthesis says "do not include this endpoint as part of the solution set". Note the open hole at x = -2 in the diagram.
In contrast, the value x = 4 is included (due to the filled in circle), so we use a square bracket for this endpoint. Therefore, the right-hand portion is represented by [4, ∞) which translates to
Negative and positive infinity will always use a parenthesis, and never a square bracket. This is because we can only approach infinity but never reach it, so we cannot include it as an endpoint.
All of this builds up to the full interval notation to be
The only square bracket is near the 4; everything else is a curved parenthesis. This is why choice D is the final answer.
Answer: the value of her investment after 4 years is £8934.3
Step-by-step explanation:
The formula for determining compound interest is expressed as
A = P(1+r/n)^nt
Where
A = total amount in the account at the end of t years
r represents the interest rate.
n represents the periodic interval at which it was compounded.
P represents the principal or initial amount invested.
t represents the duration of the investment in years.
From the information given,
P = 8000
r = 2.8% = 2.8/100 = 0.028
n = 1 because it was compounded once in a year.
t = 4 years
Therefore,
A = 8000(1+0.028/1)^1 × 4
A = 8000(1+0.028)^4
A = 8000(1.028)^4
A = £8934.3 to the the nearest penny