Answer:
a)
i.the lower limit of the sum
: n=1
ii.the upper limit of the sum
: n=18
iii.the explicit formula of the sum
: [tex]a_n=7n-4[/tex]
b) 1,125 beads
Step-by-step explanation:
a) The number of beads per row of Dante's necklace is given by the series:
3 + 10 + 17 + 24 + ...
The first term of this series is [tex]a_1=3[/tex].
There is a constant difference of [tex]d=10-3=7[/tex].
To write this series in summation notation, we need to determine the explicit formula which is given by:
[tex]a_n=a_1+d(n-1)[/tex]
We plug in the values to get:
[tex]a_n=3+7(n-1)[/tex]
[tex]\implies a_n=3+7n-7[/tex]
[tex]\implies a_n=7n-4[/tex]
The summation notation is given by:
[tex]\sum^{18}_{n=1}(7n-4)[/tex]
b) The total number of beads in the necklace is given by the sum of the first 18 terms of the sequence.
This is given by [tex]S_n=\frac{n}{2}(2a_1+d(n-1))[/tex]
We substitute the values to obtain:
[tex]S_{18}=\frac{18}{2}(2\cdot3+7(18-1))[/tex]
[tex]S_{18}=9(6+119)[/tex]
[tex]S_{18}=9(125)[/tex]
[tex]S_{18}=1125[/tex]
Therefore the total number of beads is 1125
The arithmetic series 3, 10, 17, 24,... in which each term increases by 7 can be described in summation notation with a lower limit of 1, an upper limit of 18, and an explicit formula of 7n - 4. The total number of beads in Dante's 18-row necklace, computed using the arithmetic series sum formula, is 1125 beads.
Explanation:The series described here is an arithmetic series, where each term increases by the same amount, 7 in this case.
a. To express this series in summation notation, you must know:
The lower limit of the sum: In the series, the first term is 3, so the lower limit, often denoted as n, is 1.The upper limit of the sum: As there are 18 rows, n, or the number of terms in our sum, will be 18.The explicit formula for the sum: For an arithmetic series, the sum is given by the formula S = n/2 * (a + l) where n is the number of terms, a is the first term and l is the last term. However, we need the general term to express the series in summation notation, which is given by a + (n-1)d in an arithmetic progression. Here, a=3 and d, the difference is 7. So the general term is 3 + (n-1)*7 = 7n - 4.b. To find the total number of beads in the necklace, you use the formula for the sum of an arithmetic series. For the last term, l, we use the formula a+(n-1)d = 3+(18-1)*7 = 122. Hence, the total number of beads is S = 18/2 * (3 + 122) = 1125.
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Zhi bought 18 tickets for games at a fair. Each game requires 3 tickets. Zhi wrote the expression 18 – 3g to find the number of tickets she has left after playing g games. Diego correctly wrote another expression, 3(6 – g), that will also find the number of tickets Zhi has left after playing g games. Use the drop-down menus to explain what each part of Zhi's and Diego's expressions mean.
Yes, Zhi's expression multiplies the tickets per game by the number of games to get the number of tickets used and then subtracts this amount from the total tickets.
Jade is painting a rectangular wall. The wall is 414 yards long and 223 yards high.The formula for the area of a rectangle is A=bh. What is the area of the wall?
The formula for the area of the rectangle is actually A = LW. The length of the rectangular wall is 414 yards while its width is 223 yards. To compute for its area, you just have to follow the formula:
A = 414 (223)
A = 92,322 yards^2
Therefore, the area of the wall is 92,322 square yards.
Answer:
hey the answer is 11 1/3
Step-by-step explanation:
ive taken the quiz and this is the answer 100%
If the measurement of a central angle is 77 degrees find the length of its intercepted arc in a circle with a radius of 15 inches.
Answer:
20.2 inches ;)
Step-by-step explanation:
Rewrite the radical exponent as a radical
Use the data to create a scatter plot.
Size (lb)
8
12
9.5
5
7
7.5
Time (h)
5
6.5
4
3.5
2
5
1. Suppose that the amount of algae in a pond doubles every 4 hours. If the pond initially contains 90 pounds of algae, how much algae will be in the pond after 12 hours? (1 point)
would it be 720lbs
Angle A is a right angle in △ABC.
Which side is opposite to angle A?
side BC
side AB
side AC
Option 1 is correct. The side opposite to angle A is side BC, which is the hypotenuse.
In a triangle, the side opposite the right angle is known as the hypotenuse. Since angle A is given as a right angle in △ABC, the side opposite this right angle will be the hypotenuse.
In △ABC:
Side AB is adjacent to angle A, forming one leg of the right triangle.
Side AC is also adjacent to angle A, forming the other leg of the right triangle.
Side BC is opposite angle A and is the longest side of the triangle, making it the hypotenuse.
Therefore, side BC is opposite to angle A in △ABC.
Complete question:
Angle A is a right angle in △ABC.
Which side is opposite to angle A?
1. side BC
2. side AB
3. side AC
plz help "geometry"
the intersection of roads M and N creat a 71.4 degrees what are the complumentry and suplumentry angels of this intersection
A 161.4' ; 18.6'
B 18.6'; 161.4'
C 108.6' ; 18.6'
D 18.6' ; 108.6',
a/an ______ angle measures less than 90degrees°, a/an ______ angle measures 90degrees°, a/an ______ angle measures more than 90degrees° and less than 180degrees°, and a/an ______ angle measures 180degrees°.
if she can read 22 pages in 1 hour how many hours did she read in 114.5 hours
NEED HELP ASAP!
to find the height of a pole, a surveyor moves 120 feet away from the base of the pole and then, with a transit of 8 feet tall, measures the angle of elevation to the top of the pole to be 36°. to the nearest foot, what is the height of the pole?
a. 87 feet
b. 95 feet
c. 71 feet
d. 79 feet
Answer:
95 feet
Step-by-step explanation:
Refer the attached figure.
A surveyor moves 120 feet away from the base of the pole i.e. BC = 120 feet.
BC= ED = 120 feet (refer the figure)
Height of transit i.e. DC = 8 feet
DC = EB = 8 feet (refer the figure)
The angle of elevation to the top of the pole to be 36° i.e. ∠ADE = 36°
Height of pole = AE+EB
To find AE use trigonometric ratio
[tex]tan\theta = \frac{Perpendicular}{Base}[/tex]
[tex]tan36^{\circ}= \frac{AE}{ED}[/tex]
[tex]0.726= \frac{AE}{120}[/tex]
[tex]0.726*120= AE[/tex]
[tex]87.12 = AE[/tex]
Height of pole = AE+EB = 87.12+8 = 95.12 feet≈95 feet
Hence the height of pole is 95 feet
Ashur solves the following system of linear equations.
Which statement about the solution to this system can he say is true?
The values of a and b are both equal to –4.
The values of a and b are both equal to 4.
The value of a is equal to 4, and b is equal to –4.
The value of a is equal to –4, and b is equal to 4.
The given equations that make up the systems are:
-3a+7b=-16...................(Equation 1)
-9a+5b=16...................(Equation 2)
To find the values of a and b we will have to solve the two equations. To solve the equations let us employ the method of elimination.
Let us multiply (Equation 1) by -3. This will give us:
[tex] -3\times (-3a+7b=-16)=9a-21b=48 [/tex]...........(Equation 3)
Let us now add (Equation 2) to (Equation 3) to eliminate a. This will give us:
-16b=64
[tex] \therefore b=-4 [/tex]
Plugging this value of b in any of the equations we will get the value of a. Let us plug it in (Equation 1). This gives:
[tex] -3(-4)+7b=-16 [/tex]
[tex] 12+7b=-16 [/tex]
[tex] \therefore b=\frac{-28}{7}=-4 [/tex]
Thus, out of the given options, the first option is the correct one. The values of a and b are both equal to –4.
What is the solution of the equation 5x – 1 = 45? Round your answer to the nearest ten-thousandth
Final answer:
The solution to the equation 5x – 1 = 45 is x = 9.2, rounded to the nearest ten-thousandth.
Explanation:
The solution of the equation 5x – 1 = 45 is x = 9.2.
To solve this equation, we can start by isolating the variable x. Add 1 to both sides of the equation to get 5x = 46. Then, divide both sides by 5 to solve for x, giving us x = 9.2.
Therefore, the solution to the equation 5x – 1 = 45 is x = 9.2, rounded to the nearest ten-thousandth.
50 points! Dustin and Melanie are playing a game, where two standard, six-sided number cubes are rolled, and the sum of their outcomes is found. Each player gets a chance to guess the correct sum, and the player that guesses the correct sum wins the game.
Dustin decides to guess a sum of six. Melanie decides to guess a sum of seven.
Which player made the better decision? ________
Answer:
Melanie is the right answer
Step-by-step explanation:
Melanie made the better decision if Dustin and Melanie are playing a game, where two standard, six-sided number cubes are rolled.
What is probability?It is defined as the ratio of the number of favorable outcomes to the total number of outcomes, in other words, the probability is the number that shows the happening of the event.
We have:
Dustin and Melanie are playing a game, where two standards, six-sided number cubes are rolled.
If the sum is 6:
The possible outcomes are = {(3,3), (2,4), (4,2), (1,5), and (5,1)}
Total outcomes = 5
If the sum is 7:
The possible outcomes are = {(1,6), (6,1), (5,2),( 2,5), (3, 4), (4,3)}
Total outcomes = 7
Thus, Melanie made the better decision if Dustin and Melanie are playing a game, where two standards, six-sided number cubes are rolled.
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In ∆TUV, Y is the centroid. If TW = 30, what is YW?
Answer:
answer is 10
Step-by-step explanation:
How long would it take to travel 630 miles at the rate of 35 miles per hour? 18 h 35 h 220 h 350 h
Answer:
18h
Step-by-step explanation:
two positive integers have a sum of 17 and a product of 66
The amount of grass seed needed to cover a lawn is proportional to its area. The lawn is rectangular and has an area of 2c^2 + 2c square meters. Factor this polynomial to find possible expressions for the length and width of the lawn. (Assume the factors are polynomials.) HELP ASAP!!
If mAD=85 degrees and mBC=31 degrees find the value
By the properties of angles on a circle, the degree measure of x in the circle is 11 degrees
Calculating the degree measure of xFrom the question, we have the following parameters that can be used in our computation:
The circle
The angle in a circle is 360 degrees.
So, we have
Unused arcs = 360 - 85 - 31
Unused arcs = 244
This means that
2(13x - 21) = 244
So, we have
13x - 21 = 122
This gives
13x = 143
Evaluate
x = 11
Hence, the degree measure of x is 11 degrees
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How do you determine whether to draw the boundary line of the graph of a linear inequality dashed or solid?
Number 11 please....
The DIAMETER of a sphere is doubled. What is the new volume of the sphere?
A)
8/3πr3
B)
16/3πr3
C)
32/3πr3
D)
64/3πr3
at 4:00 am,there were 800,000 gallons of water remaining at a reservoir.after 4 hours of irrigation,there were 100,000 gallons of water remaining.write an equation that describes the number of gallons of water as a function of the time the field has been irrigated
What is the period for the graph of y
which of the following are polynomial functions?check all that apply
(answers in picture)
Answer:
Step-by-step explanation: It is only c and e i just did the test.
What happens when you square a cubed root or cube a square root and problems like these. Please tell me how to do it!
The first term of a sequence is -12. The recursive formula for the sequence is an = an-1 + 9. What are the next 3 terms in the sequence?
what is the answer to f(2)=2-5(2)
which is the directrix of parabola with equation x^2=4y
Answer:
[tex]y=-1[/tex]
Step-by-step explanation:
We have been given an equation of parabola [tex]x^2=4y[/tex]. We are asked to find the directrix of our given parabola.
First of all, we will divide both sides of our given equation by 4.
[tex]\frac{x^2}{4}=\frac{4y}{4}[/tex]
[tex]\frac{x^2}{4}=y[/tex]
[tex]y=\frac{x^2}{4}[/tex]
Now, we will compare our equation with vertex form of parabola:
[tex]y=a(x-h)^2+k[/tex], where, (h,k) represents vertex of parabola.
We can see that the value of a is [tex]\frac{1}{4}[/tex], [tex]h=0[/tex] and [tex]k=0[/tex].
Now, we will find distance of focus from vertex of parabola using formula [tex]p=\frac{1}{4a}[/tex].
Substituting the value of a in above formula, we will get:
[tex]p=\frac{1}{4*\frac{1}{4}}[/tex]
[tex]p=\frac{1}{1}=1[/tex]
We know that directrix of parabola is [tex]y=k-p[/tex].
Substituting the value of k and p in above formula, we will get:
[tex]y=0-1[/tex]
[tex]y=-1[/tex]
Therefore, the directrix of our given parabola is [tex]y=-1[/tex].
) the length of a rectangle is 5 cm less than twice the width. if the area of the rectangle is 88 , find the dimensions of the rectangle.