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Fed [463]
3 years ago
9

PLEASE HELP ME!

Mathematics
1 answer:
algol133 years ago
5 0

Step-by-step explanation:

1.\sum_{i=1}^{5}3i

The simplest method is "brute force".  Calculate each term and add them up.

∑ = 3(1) + 3(2) + 3(3) + 3(4) + 3(5)

∑ = 3 + 6 + 9 + 12 + 15

∑ = 45

2.\sum_{k=1}^{4}(2k)^{2}

∑ = (2×1)² + (2×2)² + (2×3)² + (2×4)²

∑ = 4 + 16 + 36 + 64

∑ = 120

3.\sum_{k=3}^{6}(2k-10)

∑ = (2×3−10) + (2×4−10) + (2×5−10) + (2×6−10)

∑ = -4 + -2 + 0 + 2

∑ = -4

4. 1 + 1/4 + 1/16 + 1/64 + 1/256

This is a geometric sequence where the first term is 1 and the common ratio is 1/4.  The nth term is:

a = 1 (1/4)ⁿ⁻¹

So the series is:

\sum_{j=1}^{7}(\frac{1}{4})^{j-1}

5. -5 + -1 + 3 + 7 + 11

This is an arithmetic sequence where the first term is -5 and the common difference is 4.  The nth term is:

a = -5 + 4(n−1)

a = -5 + 4n − 4

a = 4n − 9

So the series is:

\sum_{j=1}^{5}(4j-9)

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zvonat [6]
Hey.
The answer is (7,4).
The change of x is -6. Divide that by two(=-3) and add it to the first x-coord and you get 7.
Do the same for your y-value(change =+6/2= +3) and you'll get 4.
6 0
3 years ago
What is the value of x?
Angelina_Jolie [31]

Answer:

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Step-by-step explanation:

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cross-multiply:

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x = 5.4

5 0
3 years ago
Select the possible values for x in the equation x2 = 108.
Rudiy27

Answer:

D. 6√3.

Step-by-step explanation:

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x = +/- 6√3

7 0
3 years ago
What is x in this equation −4.5= −0.5(x − 7.1)
Umnica [9.8K]

Answer:

x=16.1

Step-by-step explanation:

-4.5= -0.5(x -7.1)

Divide both sides by -0.5

9=x-7.1

Add 7.1 to both sides

16.1=x

Hope this helps!

7 0
3 years ago
A ballroom in a hotel has the shape shown. The manager needs to determine how much carpet is needed to recarpet this area. All a
Mars2501 [29]
Area of a rectangle=length x width


You have two rectangles:


First rectangle (the biggest):
length=9 yd
width=12 yd-6 yd=6 yd

Area of the biggest rectangle=(9 yd)(6 yd)=54 yd²

Second rectangle (the smallest)
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Area of the ballroom=area of the biggest rectangle + area of the smallest rectangle.

area of the ballroom=54 yd² +18 yd²=72 yd²
7 0
2 years ago
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