Given an arithmetic progression 17,13,9,..... find the number of terms required so that its sum is - 33 .

Answers

Answer 1

Answer:

11 terms.

Step-by-step explanation:

We are given the arithmetic sequence:

17, 13, 9, ...

And we want to find the number of terms required such that the sum is -33.

Recall that the sum of an arithmetic series is given by:

[tex]\displaystyle S = \frac{k}{2}\left( a + x_k\right)[/tex]

Where k is the number of terms, a is the first term, and x_k is the last term.

The desired sum is -33. The first term is 17 as well. Thus:

[tex]\displaystyle (-33) = \frac{k}{2} \left( (17) +x_k\right)[/tex]

Simplify:

[tex]-66 = k(17 + x_k)[/tex]

We can write a direct formula to find the last term x_k. The direct formula of an arithmetic sequence has the form:

[tex]x_ n = a + d(n-1)[/tex]

Where a is the initial term and d is the common difference.

The initial term is 17 and the common difference is -4. Hence:

[tex]\displaystyle x_n = 17 - 4(n-1)[/tex]

Then the last term is given by:

[tex]x_k = 17 - 4(k-1)[/tex]

Substitute:

[tex]\displaystyle -66 = k\left( 17 + \left( 17 - 4(k-1)\right)\right)[/tex]

Solve for k:

[tex]\displaystyle \begin{aligned} -66 &= k(17 + (17 - 4k + 4)) \\ -66 &= k(38 -4k) \\ -66 &= -4k^2 + 38k \\ 4k^2 -38k -66 &= 0 \\ 2k^2 - 19k -33 &= 0 \\ (k-11)(2k+3) &= 0 \\ k-11&= 0 \text{ or } 2k+3 = 0 \\ \\ k &= 11 \text{ or } k = -\frac{3}{2}\end{aligned}[/tex]

Since we cannot have a negative amount of terms, we can ignore the second solution.

Therefore, the given sequence must have 11 terms such that it sums to -33.

Answer 2

Answer:

Here is 2 methods

Step-by-step explanation:

1) we use excel to find n=11 for lasy students

2) mathematical method

[tex]u_1=17\\u_2=13=17+(2-1)*(-4)\\u_3=9=17+(3-1)*(-4)\\\\\\\boxed{u_n=17+(n-1)*(-4)}\\\\\\\displaystyle s_n=\sum_{i=1}^nu_i\\=\sum_{i=1}^n(17+(i-1)*(-4))\\\\\\=(\sum_{i=1}^n 17) + (-4)*\sum_{i=1}^n (i) +4*\sum_{i=1}^n (1)\\\\\\=17*n+4*n-4*\frac{n*(n+1)}{2} \\\\\\=21n-2n^2-2n\\\\\\=-2n^2+19n\\\\=-33\\\\\\\Longrightarrow\ 2n^2-19n-33=0[/tex]

[tex]\Delta=19^2+4*2*33=625=25^2\\\\n=\dfrac{19-25}{4} =-1.5\ (excluded)\ or\ n=\dfrac{19+25}{4}=11\\\\[/tex]


Related Questions

Does this set of ordered Paris represent a function? Why or why not

Answers

Answer:

Me = no it doesn't....

you = why tho

me = becoz function not given .....

so lame joke ik...

Pls help I tried basic answers like 50+50+80 =180 but it’s wrong so pls help

Answers

Answer:

x = 65 degrees

Step-by-step explanation:

x° + x° + 50° = 180°

2x + 50° = 180°

2x = 180° - 50°

2x = 130°

x = 130°/2

x = 65°

Simplify: 5^(x+2)-4×5^x÷21×5^x​

Answers

Answer:

(1/21)(21×5^(x+2)-4×5^2x)

Step-by-step explanation:

5^(x+2)-4×5^x÷21×5^x

= 5^(x+2)-4×5^2x/21

= 1/21(21×5^(x+2)-4×5^2x)

UDISJKDFJSFJDGLFS HELP

Answers

Answer:

I think E

Step-by-step explanation:

You know the shortest building is 25 m.

to find the rest, use trigo so Tan(20)=opposite/adjacent.

Adjacent is 50. Do the math and add the answer with 25.

Answer:

The answer would be E. 43.2

According to TOA, The opposite side is tan(20) x adjacent side( 50m)

the answer is 18.2( to 1 dp). Add the height of the second building together with 18.2 and you will get ur answer. HOpe this helps:)

The points A,B,C and D divide the line segment AD in the ratio 4:3:1 , respectively , and AD = 72cm . What is the length of BD?

Answers

Segment addition postulate states that given points X, and Z, on a line, a point Y, can be located between X, and Z, ony if we have;

XZ = XY + YZ

The length of the segment BD is 36  cm

The reason the above value is correct is as follows:

Known:

The ratio in which the points A, B, C, and D divide the line segment = 4:3:1

The length of segment AD = 72 cm

Required:

The length of BD

Method:

Calculate the length of BC and CD and add their values to get BD

Solution:

Let the ratios be given unit proportions of the segment AD such that we have;

AB = 4 units

BC = 3 units

CD = 1 unit

By segment addition postulate, we have;

AD = AB + BC + CD

∴ AD = 4 units + 3 units + 1 unit = 8 units = 72 cm

∴ 1 unit = 72 cm/8 = 9 cm

1 unit = 9 cm

BD = BC + CD by segment addition postulate

BC = 3 units = 3 × 1 unit

∴ BC = 3 × 9 cm = 27 cm

BC = 27 cm

CD = 1 unit

∴ CD = 9 cm

∴ BD = 27 cm + 9 cm = 36 cm

The length of segment BD = 36 cm

Learn more about segment addition postulate here:

https://brainly.com/question/17015321

A recipe for eight flapjacks needs 2oz of butter, 3oz of sugar, and 4 oz of rolled oats. How many flapjacks can I make if I have 14 oz of butter, 15 oz of sugar, and 16 oz of rolled oats?

Answers

Answer:

Step-by-step explanation:

Eight flapjacks

2oz of butter

3oz of sugar

4 oz of rolled oats.

Each flapjack

Butter = 2/8 = 1/4 oz

Sugar = 3/8 oz

Rolled oats = 4/8 = 1/2 oz

How many flapjacks can I make if I have

14 oz of butter,

15 oz of sugar, and

16 oz of rolled oats?

Butter

= 14 oz ÷ 1/8 oz

= 14 × 8/1

= 112 flapjack

Sugar

= 15 oz ÷ 3/8 oz

= 15 × 8/3

= 120/3

= 40 flapjacks

Rolled oats

16 oz ÷ 1/2 oz

= 16 × 2/1

= 32 flapjack

Therefore,

Considering the quantity of rolled oats available, the number of flapjacks that could be made is 32

Simplify 2m^2 – 2m + 3m^2

Answers

Answer:

5m^2-2m

Step-by-step explanation:

2m^2-2m + 3m^2

5m^2-2m

Answer:

5m² - 2m

Step-by-step explanation:

Given

2m² - 2m + 3m² ← collect like terms

= (2m² + 3m²) - 2m

= 5m² - 2m

I’m having a lot of trouble, can someone guide me, step by step?

Answers

Answer:

Hi hopefully this helps you!

Step-by-step explanation:

To find the area of a circle you can use the formula A = πr^2

The radius of a circle is just the diameter divided by 2. In this case we know the diameter is 3, so the radius is 1.5

A = π(1.5)^2

   = 7.07

Because this is a semicircle, divide this area by 2

   = 3.53429 in^2

Add up the area of this semi circle with the area of the rectangle

A = (3.53429) + (3x4)

   = 15.53429 in^2

To find the circumference/ perimeter of a circle use this formula C = 2πR

C = 2π(1.5)

   = 9.42478 inches

Again because this is a semicircle, divide by 2

   = 9.42478 / 2

   = 4.71239 inches

To find the perimeter of this entire shape add up the circumference of the semicircle and the rectangle's sides and bottom

P = 4.71239 + 4 + 4 + 3

  = 15.71239 inches

So the final answer would be

A = 15.53 squared inches

P = 15.71 inches

Hope this helps! Best of luck in your studies <3

Help me please and thank you

Answers

Answer:

Below

Step-by-step explanation:

The domain tells you if there are any restrictions on the x's

The -5 in the function tells us that it has moved 5 units RIGHT from the original parent function. Because of this, any x coordinates have to be bigger or equal to 5!

So, the domain of this function is x >/ 5

Hope this helps!

A new site offers a subscription that costs 28.50 for 6 months.what is unit rate price per month? show ur work

Answers

Answer:

The answer is 4.75

Step-by-step explanation:

Since six months is 28.50 then 1 month is equal to x

       28.50: 6 months

           x     : 1 month

 After this  you cross multiple so u divide by 6 both side to get 4.75

   6x/6: 28.50/6

   x=4.75

PLEASE HELP!

Find an equation in standard form for the ellipse with the vertical major axis of length 16 and minor axis of length 10.

Answers

Refer the attached image for the answer

HOPE SO IT HELPS YOU

The measures of two angles of a triangle are 36 degree and 75 degree . The length of the shortest side of a triangle is 10 cm . The length of longest side of the triangle is:?

Answers

Hope it’s helps
You can text me if you don’t understand anything

Jesse travels 3.0 meters east and then turns and travels 4.0 meters north. The trip requires 35 seconds. What is his velocity?

Answers

Using Pythagorean triplet

[tex]\\ \sf\longmapsto AB^2=AC^2-BC^2[/tex]

[tex]\\ \sf\longmapsto AB^2=4^2-3^2[/tex]

[tex]\\ \sf\longmapsto AB^2=16-9[/tex]

[tex]\\ \sf\longmapsto AB^2=7[/tex]

[tex]\\ \sf\longmapsto AB=\sqrt{7}[/tex]

Now time=35

[tex]\\ \sf\longmapsto Velocity=\dfrac{Displacement}{Time}[/tex]

[tex]\\ \sf\longmapsto Velocity=\dfrac{\sqrt{7}}{35}[/tex]

[tex]\\ \sf\longmapsto Velocity=\dfrac{2.6}{35}[/tex]

[tex]\\ \sf\longmapsto Velocity=0.07m/s[/tex]

**25 POINTS**
Which of the following lists of ordered pairs is a function?

Answers

Answer: A

Step-by-step explanation: A function is when every domain (x value) corresponds to one range (y value) so that it passes the vertical line test

Graph the line that passes through (5, 5), and is perpendicular to a line whose slope is –2.

Answers

Answer:

y = 1/2x + 5/2

Step-by-step explanation:

y = 1/2x + b

5 = 1/2(5) + b

5 = 5/2 + b

5/2 = b

ASAP HELP PLS NO WRONG ANSWERS------------

Answers

Answer

d = 12

Step-by-step explanation:

square root 4y - 3 = d - y where y = 7

Substitute y for 7

Square root 4(7) - 3 = d - (7)

Multiply 4 and 7

Square root 28 - 3 = d - (7)

Subtract 28 - 3

Square root 25 = d - (7)

Square root 25

5 = d - (7)

Add 7 to both sides

12 = d


Therefore, d = 12

Answer:

d=2

Step-by-step explanation:

We are given equation:

sqrt(4y-3)=d-y

Squaring both sides gives:

4y-3=(d-y)^2

Applying the identity (x+y)^2=x^2+2xy+y^2 on right:

4y-3=d^2-2dy+y^2

Now let's y=7:

4(7)-3=d^2-2d(7)+(7)^2

Simplify:

25=d^2-14d+49

Subtract 25 on both sides:

0=d^2-14d+24

Factor left:

0=(d-12)(d-2) since -2+-12=-14 and -2(-12)=24

This gives d=12 or d=2.

The d that makes d-y or I mean d-7 negative will give us y=7 as extraneous

Since 2-7 is -5, then d=2 is what we are looking for.

Check:

sqrt(4y-3)=d-y

Set d=2: sqrt(4y-3)=2-y

Now solve for y:

Square both sides: 4y-3=4-4y+y^2

Subtract 4y and 3 on both sides: 0=7-8y+y^2

Reorder right side: 0=y^2-8y+7

Factor: 0=(y-7)(y-1) since -7+-1=-8 and -7(-1)=7

This gives y=7 or y=1.

Plugging in y=7 for a check to this equation gives:

sqrt(4×7-3)=2-7

Sqrt(25)=-5

5=-5 which is not true which is what we wanted

PLS HELP ME ON THIS QUESTION I WILL MARK YOU AS BRAINLIEST IF YOU KNOW THE ANSWER PLS GIVE ME A STEP BY STEP EXPLANATION!!

Answers

Answer:

(-5,2)

Step-by-step explanation:

Answer:

(5 , 2)

Step-by-step explanation:

F(-5 , 2)

After reflection F'(5 , 2)

The rule for reflection over y-axis is

Original point(x , y)   :  After reflection:  (-x,y)

x-coordinate will change its sign and y-coordinate remains same

the prouduct of any two irrational number is​

Answers

Answer:

mostly rational but sometimes irrational

The product of any two irrational number can be rational or irrational depending on the two numbers.

Isabel and Sophia share a bag of 42 sweets. Isabel has 16 sweets. Find the ratio of Sophia's sweets to Isabel's sweets.

Answers

Answer:

ratio of Sophia's sweets to Isabel's sweets is

13:8

Answer:

you first have to find the number of sweets that sophia got.by subtracting the total number of sweets minus the number of sweets that isabel got which will be

42-16=26

therefore the ratio will be

16:26

8:13

I hope this helps

1. The mayor of the city of Cleveland wants to increase taxes in order to invest in a light-rail transit system. She hires a polling agency to randomly
select 750 registered voters in the city to survey in order to determine the maximum percentage increase in municipal taxes that they would
approve. What is the population in this survey and the population parameter?
All American citizens and the maximum percentage increase in taxes
750 registered voters in Cleveland and the average light-rail transit cost per mile
O All registered voters in Cleveland and the maximum percentage increase in taxes
O Citizens over 65 years of age in Cleveland and the 750 registered voters

Answers

Answer:

All registered voters in Cleveland and the maximum percentage increase in taxes

Categorize the graph as linear increasing, linear decreasing, exponential growth, or exponential decay

Answers

Answer:

D. Exponential growth

Step-by-step explanation:

Hope this helps

Function that is similar to exponential.

Option (A) is correct.

What is exponential decay?

Exponential decay describes the process of reducing an amount by a consistent percentage rate over a period of time. It can be expressed by the formula  [tex]y=a(1-b)^{x}[/tex] wherein y is the final amount, a is the original amount, b is the decay factor, and x is the amount of time that has passed.

We can observe that

First, y increases as x increases

Last it is a function that is similar to exponential.

Function is an exponential decay.

Option (A) is correct.

Find out more information about exponential decay here

https://brainly.com/question/14355665

#SPJ2

Does this graph show a function? Explain how you know.
A. No; the graph fails the vertical line test.
• B. No; there are y-values that have more than one x-value.
• C. Yes; the graph passes the vertical line test.
D. Yes; there are no y-values that have more than one x-value.

Answers

Answer:

C. Yes; the graph passes the vertical line test.

Step-by-step explanation:

Reasons the others are wrong:

A. It does pass the vertical line test.

B. Y-values can have any x values. It is x-values that can't have multiple y-values.

D. There are y-values with more than one x-value on this graph so that's just false. Even if it were true, that still doesn't invalidate it due to the reasons given in Answer B.

Find the measure of <3. 90 50 40 130

Answers

Answer:  90 degrees

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

Explanation:

This figure is a kite since we have two pairs of adjacent sides that are congruent, but not all sides are the same length.

One property of kites is that the diagonals are always perpendicular (this applies to rhombuses as well). This means angle 3 is 90 degrees.

The measure of ∠3 is 90°

Because in a kite the diagonals bisects at 90°

Therefore ∠3 is 90°

Answered by Gauthmath must click thanks and mark brainliest

Explain how to solve the equation
.
b – 7 = 12

Answers

Answer:

19

Step-by-step explanation:

Add 7 onto 12 to find answer.

Answer:

b = 19

Step-by-step explanation:

b = 12 + 7

Simplify 12+7 to 19.

What is the solution to the system that is created by the equation y = - x + 6

Answers

Answer:

If you draw the graph of y = -x + 6  on the above graph  the solution to system will be the coordinates of the point of intersection.

the equation of the line drawn above is y = 0.5x

so you can also find the solution by solving the system

y = 0.5x

y = -x + 6

0.5x = -x + 6

1.5x = 6

x = 6/1.5 = 4

and y = 0.5*4 = 2

The answer is  (4, 2)     - the third choice.

Step-by-step explanation:

Will Mark Brainlest Help pls​

Answers

Answer:

Hello,

[tex]\begin{bmatrix}-2&2\\3&5\\\end{bmatrix}\\\\[/tex]

Step-by-step explanation:

[tex]\begin{bmatrix}2&3\\5&7\end{bmatrix}-A=\begin{bmatrix}3&1\\-2&-3\end{bmatrix}+\begin{bmatrix}1&0\\0&1\end{bmatrix}\\\\\\\begin{bmatrix}2&3\\5&7\end{bmatrix}-A=\begin{bmatrix}2&3\\5&7\end{bmatrix}-\begin{bmatrix}4&1\\-2&-2\end{bmatrix}\\\\\\A=\begin{bmatrix}-2&2\\3&5\end{bmatrix}\\\\[/tex]

On another map, the distance between Saugerties and
Kingston is 2 inches. What would the distance from
Saugerties to Catskill be on this map?

Answers

Answer:

10miles

Step-by-step explanation:

Answer:

I have no clue what is going on wit dis g

find the missing side.​

Answers

Answer:

I htink x ≈ 8

Step-by-step explanation:

Answer:

X is approximately 7.8.

Step-by-step explanation:

You can use SOH-CAH-TOA to help figure out what function (sin, cos, tan) you need to use in order to figure out the missing side.

For this one, we can see the angle is pointing to the opposite side (x length), and we have been given the hypotenuse (18). So we want to use the sin function.

[tex]sin\ (angle)=\frac{opposite}{hypotenouse}[/tex]

[tex]sin (26)=\frac{x}{18}[/tex]

[tex]0.438=\frac{x}{18}[/tex]

[tex]7.890... = x[/tex]

Using Pythagorean theorm, you can figure out the other side if need be :)

For reference:

[tex]sin (angle)=\frac{opposite}{hypotenuse}[/tex]

[tex]cos(angle)=\frac{adjacent}{hypotenuse}[/tex]

[tex]tan(angle)=\frac{opposite}{adjacent}[/tex]

value of the pronumeral and describe the rule.
4,1,-2,p,-8,-11​

Answers

Answer:

p = -5

every element in the sequence is created by subtracting 3 from the pervious element.

Step-by-step explanation:

I am not sure you put every necessary information here.

but I'd the visible information is truly everything, then it's is trivial.

the difference between 4 and 1 is ... well, -3. meaning we subtract 3 from 4 to get 1.

we suspect this is the rule and keep trying.

1 -3 = -2

hey it works.

and -8 -3 = -11

hey, also correct.

and the difference between -2 and -8 is -6, and when we place another item in between (p), we cut that in half again to -3. so, it is all consistent.

therefore,

p = -2 -3 = -5

the rule is

an = an-1 - 3

-2z² + 4z + 2z² = ?
Anyone know this? ​

Answers

Answer:

4

Step-by-step explanation:

Let's simplify step-by-step.

−2z2+4z+2z2

Combine Like Terms:

=−2z2+4z+2z2

=(−2z2+2z2)+(4z)

=4z

Answer:

4z

Hope this helps <3 Need thanks?

Comment /hearthelp

[tex]\\ \sf\longmapsto -2z^2+4z+2z^2[/tex]

Combine like. variables

[tex]\\ \sf\longmapsto -2z^2+2z^2+4z[/tex]

[tex]\\ \sf\longmapsto (-2+2)z^2+4z[/tex]

[tex]\\ \sf\longmapsto 0z^2+4z[/tex]

[tex]\\ \sf\longmapsto 4z[/tex]

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