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Sonja [21]
1 year ago
12

the rule for being the nth item in a certain sequence is n(n+1)/2. what is the 4th term in this sequence ? a.) 4b.)10c.)16d.)20

Mathematics
1 answer:
abruzzese [7]1 year ago
3 0

The 4th term of the sequence can be determined as,

\begin{gathered} a_n=\frac{n(n+1)}{2} \\ a_4=\frac{4(4+1)}{2} \\ a_4=10 \end{gathered}

Thus, option (b) is correct.

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Can you help me with my homework please
umka21 [38]

#4(a)

row-seat: 3- 13, 4-15, 5-17, 6-19, 7-21

(b)

the equation works for row 1 but not for any of the rows after this

Ex: Row 2, S=7(2)+2, this would equal 14 but there isn't 14 seats in row #2

(c)

S=2(1)+7, there is 9 seats in row 1

2(2)+7=11,  there is 11 seats in row 2

2(3)+7= 13, there is 13 seats in row 3

(d)

2(15)+7=37

2*15=30, 30+7=37

(e)

91=2(r)+7

91-7=2(r)+7-7

84=2(r)

84/2=2(r)/2

42=r, the row with 91 seats is row 42


3 0
3 years ago
What is 278 minus 149
Basile [38]

Answer:

129

Step-by-step explanation:

278 - 149 = 129

5 0
3 years ago
Read 2 more answers
What's the answer to this? and please explain.
vichka [17]
<h3>Answer: No, there isn't enough ribbon</h3>

===========================================================

Use this formula

a & b/c = (a*c+b)/c

to convert from a mixed number to an improper fraction

So,

a & b/c = (a*c+b)/c

3 & 3/4 = (3*4+3)/4

3 & 3/4 = 15/4

---------------------------------------------------

Next, we add the fractions 15/4 and 5/6. The denominators aren't the same, so we can't add right away. We need to get the denominators to the LCD.

In this case, the LCD is 4*6 = 24

  • The fraction 15/4 becomes 90/24 after multiplying top and bottom by 6.
  • The fraction 5/6 becomes 20/24 after multiplying top and bottom by 4

Now we can add the fractions:

90/24+20/24 = (90+20)/24 = 110/24

---------------------------------------------------

So far, we've added the 3&3/4 portion to the 5/6 portion to get the result 110/24

The last thing to do is to add on the two 1/3 ft pieces, which means we're adding on 2/3 of a foot

2/3 = 16/24 after multiplying top and bottom by 8

Add this to the result of the last section

110/24+16/24 = (110+16)/24 = 126/24

---------------------------------------------------

From here, we convert the improper fraction 126/24 to decimal form

Using a calculator, you should find that 126/24 = 5.25

The result is larger than 5, which means she used too much ribbon. There won't be enough ribbon to do everything she wants to do.

---------------------------------------------------

The shortcut we can take is to type the following into the calculator

3+3/4+5/6+2/3

doing so should lead to 5.25

5 0
3 years ago
Read 2 more answers
The formula for the area of a circle is A=pir^2. Find the area of a circle with a diameter of 6.4 centimeters. Use a calculator
Advocard [28]
A=pi(3.2)^2= 32.1699087728
A=32cm^2
3 0
4 years ago
PLEASE HELP. I NEED HELP, I NEEEEEEED HELP
yuradex [85]

Answer:

1. r is point

2.PQ is ray

3. pr is line

4. p.q,r is collnear points

5. QR is segment

6 0
3 years ago
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