Answer:
y= 1200(0.92)^x
Step-by-step explanation:
Given data
Cost price= $1200
Rate of decrease= 8%
Let the time be x
The expression that describes an exponential function is
y= ab^x
for decrease b= 1-r
y= 1200(1-0.08)^x
y= 1200(0.92)^x
Hence the expression is
y= 1200(0.92)^x
2x + 5y + 7x
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Combine like terms
(2x + 7x)
---
9x + 5y
Simplify both sides if needed. The left-hand side needs simplification.
4(x - 6)
-2x + 6
4x - 24
-2x + 6
All is left to do is add and subtract to get the x variable all alone.
4x - 24
-2x + 6
6x - 24
6 <-- Add 2x to both sides
6x
30 <-- Add 24 to both sides
x
5 <-- Divide both sides by 6
In order to be in the solution set, x has to be less than or equal to 5.
In interval notation: [5, -∞)
The 21st term of the given arithmetic sequence is 83. The nth term of an arithmetic sequence is applied to find the required value where n = 21.
<h3>What is the nth term of an arithmetic series?</h3>
The nth term of an arithmetic sequence is calculated by the formula
aₙ = a + (n - 1) · d
Here the first term is 'a' and the common difference is 'd'.
<h3>Calculation:</h3>
The given sequence is an arithmetic sequence.
3, 7, 11, 15, 19, ....
So, the first term in the sequence is a = 3 and the common difference between the terms of the given sequence is d = 7 - 3 = 4.
Thus, the required 21st term in the sequence is
a₂₁ = 3 + (21 - 1) × 4
⇒ a₂₁ = 3 + 20 × 4
⇒ a₂₁ = 3 + 80
∴ a₂₁ = 83
So, the 21st term in the given arithmetic sequence is 83.
Learn more about the arithmetic sequence here:
brainly.com/question/6561461
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340+.06(sales)
340+.06(660)
$379.60
