The formula for the value of nth term is 
= 3n + 1
Step-by-step explanation:
The formula of the nth term in the arithmetic sequence is
, where
- a is the first term of the sequence
- d is the common difference between each two consecutive terms
∵ The first term of an arithmetic sequence is equal to four
∴ a = 4
∵ The common difference is equal to three
∴ d = 3
- Substitute these values in the rule of the nth term
∵
∴ 
- Simplify it
∴ 
∴ 
The formula for the value of nth term is = 3n + 1
Learn more:
You can learn more about the sequence in brainly.com/question/7221312
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Answer:
Step-by-step explanation:
Alrighty let's do this.
We know that formula for the Area of a triangle is:
They give us the area as 
, so let's include it in the equation.
Now we reach a stage where we have 2 unknown variables! That means we can't solve it in its current state. So the idea you should have in cases like these where you have 2 or more unknown variables is, "Can I represent this one variable in terms of another variable?" In this case you can do exactly that. You can represent height in terms of length of the base. We are told the height of the triangle is 4 meters less than the base. That is telling us that 
So replace 
in the equation with 
.
You will now get:
Now we can work towards solving. Let's get simplifying.
bring everything to one side so we can make a quadratic and factor:
We get that 
.
Since we need the height of the triangle we'll need to call back on what h is. We found earlier that 
, so to find h, we just sub in our b value into that.
We find that 
The answer is 90 because 360/4 (since it is a quadrilateral) is 90 degrees
Answer:
The third option, -1/2(30) = -15
Step-by-step explanation:
If it decreases by 1/2, we know it has to be -1/2, and the days we are given are 30. We need to multiply -1/2 by 30 in order to find the water level after 30 days, which would be -15 (inches?) I hope this helped.
