i need help with the top part

The Sequence:

1 , 1+2 , 1+2+3 , 1+2+3+4, ...

here, every term is an AP. finding the general formula for the sum of the elements of each term is:

Sₙ = [tex]\frac{x}{2}(2a + (x-1)d)[/tex]        [where x = number of term, a = first term and d = common difference]

here, the first term is always 1 and so is the common difference.

Sₙ = [tex]\frac{x}{2}(2 +x-1)[/tex]

Sₙ = [tex]\frac{x}{2}(1 +x)[/tex] = [tex]\frac{1}{2}(x + x^{2})[/tex]

which is the formula for a general term in our series

now, we need to find the sum of the first n terms of this series

[tex]\displaystyle\sum_{x=1}^{n} [\frac{1}{2}(x + x^{2})][/tex]

[tex]\displaystyle\frac{1}{2} [\sum_{x=1}^{n} (x) + \sum_{x=1}^{n}(x^{2})][/tex]

in this formula, for the first term, it's just an AP from x = 1 to x = n

for the second term, we have a general formula [tex]\frac{n(n+1)(2n+1)}{6}[/tex]

[tex]\frac{1}{2}[\frac{n}{2}(2a + (n-1)d)+ \frac{n(n+1)(2n+1)}{6} ][/tex]

in this AP (first term), the first term and the common difference is 1 as well

[tex]\frac{1}{2}[\frac{n}{2}(2 + n-1)+ \frac{n(n+1)(2n+1)}{6} ][/tex]

[tex]\frac{1}{2}[\frac{n}{2}(n+1)+ \frac{n(n+1)(2n+1)}{6} ][/tex]

[tex][\frac{n}{4}(n+1)+ \frac{n(n+1)(2n+1)}{12} ][/tex]

[tex]\frac{n}{4}(n+1) [1+\frac{(2n+1)}{3} ][/tex]

[tex]\frac{n}{4}(n+1) [\frac{(3+2n+1)}{3} ][/tex]

[tex]\frac{n}{4}(n+1) [\frac{(2n+4)}{3} ][/tex]

[tex]\frac{n}{2}(n+1) [\frac{(n+2)}{3} ][/tex]

[tex]\frac{n(n+1)(n+2)}{6}[/tex]

which is the sum of n terms of the given sequence

Answer:

TR = 23

Step-by-step explanation:

first we have to find TS, so we subtract 16 from 4 to get 12. then we can add 12 and 11 to get TR

Answer:

y-intercept is (0, -8)

Step-by-step explanation:

[tex]y = {x}^{2} + 2x - 8[/tex]

At y-intercept, x is zero

substitute x as zero:

[tex]y = {(0)}^{2} + 2(0) - 8 \\ y = 0 + 0 - 8 \\ y = - 8[/tex]

Answer:

[tex]\frac{(a+b)}{a^{2} -b^{2} }[/tex] + [tex]\frac{(a-b)}{a^{2} -b^{2} }[/tex] = [tex]\frac{2a}{a^{2} -b^{2} }[/tex]

Step-by-step explanation:

Step-by-step explanation:

[tex] \frac{ \sqrt{a + b} }{ \sqrt{a - b} } + \frac{ \sqrt{a - b} }{ \sqrt{a + b} } \\ squaring \: on \: both \: sides \\ \frac{a + b}{a - b} + \frac{a - b}{a + b} \\ \frac{(a + b) \times (a + b) + (a - b)(a - b)}{(a - b)(a + b)} \\ \frac{ {(a + b)}^{2} + {(a - b)}^{2} }{ {a}^{2} - {b}^{2} } \\ remaining \: in \: attachment[/tex]

[tex]thank \: you[/tex]

Answer:

10 inches

Step-by-step explanation:

radius = 5 inches

Diameter = radius x 2 = 5 x 2 = 10 inches

Answer:

hope it helps, appreciate if you can give brainliests

Answer:

The united nations flag the translation can be any of the blue triangles and the reflection if the flag itself as it is symmetrical

Step-by-step explanation:

The united nations flag the translation can be any of blue triangles and the reflection if the flag itself as it is symmetrical.

When a graph is reflected along an axis, say x axis, then that leads the graph to go just in opposite side of the axis as if we're seeing it in a mirror.

If we study it more, you will find that its symmetric, thus each point is equidistant from the axis of reflection as that of the image of that point.

If you're reflecting a point (x,y) along x axis, then its abscissa will stay same but ordinates will negate. Thus (x,y) turns to (x, -y)

Similarly, if you're reflecting a point (x,y) along y axis, the resultant image of the point will be (-x,y)

Therefore, The united nations flag the translation can be any of blue triangles and the reflection if the flag itself as it is symmetrical.

Learn more about reflection;

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Answer:

17/30 (0.56)

Step-by-step explanation:

18/20-4/12

Reduce the fraction with 2 and 4: 9/10-1/3

Write all numerators above the least commmon denominator 30: 27-10/30

Subtract: 27-10/30 = 17/30

Answer:

semoga jawapan ini dapat membantu

Answer:

43.4 yd

Step-by-step explanation:

[tex]45^{2}[/tex]-[tex]12^{2}[/tex]

2025-144=1881

[tex]\sqrt{1881}[/tex]

43.37049

43.4

Answer:

purple.orang.blue.yellow and green

purple.orang.blue.yellow and green

Answer:

63

Step-by-step explanation:

6x + 3y - 9

x = 6

y = 9

6(6) + 3(9)

36 + 27

= 63

Answer:

After 5 seconds

Step-by-step explanation:

One is given the following expression to model to the flight path of a ball:

[tex]h=-16t^2+80t[/tex]

In this problem, one is asked to find the time at which the ball lands on the ground. The easiest way to do so is to factor the expression. Take out factors that both terms have in common. The one will set the equation equal to zero, as this is the height at which one wants to find the time for. Finally, use the zero product property to solve. The zero product property states that any number times zero equals zero. Apply these ideas to the given function:

[tex]h=-16t^2+80t[/tex]

Factor the expression; both terms have a common factor of (-16t):

[tex]h=-16t^2+80t[/tex]

[tex]h=-16t(t-5)[/tex]

Set the equation equal to zero to solve for when the ball has a height of zero or rather lands on the ground:

[tex]h=-16t(t-5)[/tex]

[tex]0=-16t(t-5)[/tex]

Now use the zero product property, this states that any number times zero equals zero. Set each of the factors equal to zero, and solve to find the value of (t) for which the factor will equal zero:

[tex]0=-16t(t-5)[/tex]

[tex]0=-16t[/tex]                          [tex]t - 5 =0[/tex]

Solve for the value (t) using inverse operations,

[tex]0=-16t[/tex]                            [tex]t - 5 =0[/tex]

(divide by (-16)                   (add (5))

[tex]0=t[/tex]                                     [tex]t=5[/tex]

As one can see, the ball started on the ground, therefore at (0) seconds, its height was (0). Then, after (5) seconds the ball landed on the ground, therefore, after (5) seconds its height was again (0).

Answer:

Below,...

Step-by-step explanation:

Your equation:

[tex]\frac{63}{7-(2*3)} =\frac{63}{7-6} =\frac{63}{1}=63[/tex]

Hope it helps,... Chow,...!

Answer:

y = 1/3mx + b

Step-by-step explanation:

x = 3(y - b)/m

~Multiply m to both sides

mx = -3b + 3y

~Add 3b to both sides

mx + 3b = 3y

~Divide everything by 3

1/3mx + b = y

y = 1/3mx + b

Best of Luck!

[tex]\\ \rm\longmapsto x=\dfrac{3(y-b)}{m}[/tex]

[tex]\\ \rm\longmapsto mx=3(y-b)[/tex]

[tex]\\ \rm\longmapsto mx=3y-3b[/tex]

[tex]\\ \rm\longmapsto 3y=mx+3b[/tex]

[tex]\\ \rm\longmapsto y=\dfrac{1}{3}mx+b[/tex]

Answer:

5(x+4)

Step-by-step explanation:

It's basically asking for the sum of a number and four to be multiplied by 5. Since the sum is made up of the unknown number and four, you'd put four and the unknown number in parenthesis while putting five on the outside, making it 5(x+4).

Answer:

[tex]tan(\theta)=\frac{\sqrt{21}}{3}[/tex]

Step-by-step explanation:

1. Approach

One is given the following information:

[tex]cos(2\theta)=-\frac{2}{5}[/tex]

One can rewrite this as:

[tex]cos(2\theta)=-0.4[/tex]

Also note, the problem says that the angle ([tex]2\theta[/tex]) is found in the third quadrant.

Using the trigonometric identities ([tex]cos(2\theta)=2(cos^2(\theta))-1[/tex]) and ([tex]cos(2\theta)=1-2(sin^2(\theta))[/tex]) one can solve for the values of ([tex]cos(\theta)[/tex]) and ([tex]sin(\theta)[/tex]). After doing so one can use another trigonometric identity ([tex]tan(\theta)=\frac{sin(\theta)}{cos(\theta)}[/tex]).  Substitute the given information into the ratio and simplify.

2. Solve for [tex](cos(\theta))[/tex]

Use the following identity to solve for ([tex]cos(\theta)[/tex]) when given the value ([tex]cos(2\theta)[/tex]).

[tex]cos(2\theta)=2(cos^2(\theta))-1[/tex]

Substitute the given information in and solve for ([tex]cos(\theta)[/tex]).

[tex]cos(2\theta)=2(cos^2(\theta))-1[/tex]

[tex]-0.4=2(cos^2(\theta))-1[/tex]

Inverse operations,

[tex]-0.4=2(cos^2(\theta))-1[/tex]

[tex]0.6=2(cos^2(\theta))[/tex]

[tex]0.3=cos^2(\theta)[/tex]

[tex]\sqrt{0.3}=cos(\theta)[/tex]

Since this angle is found in the third quadrant its value is actually:

[tex]cos(\theta)=-\sqrt{0.3}[/tex]

3. Solve for [tex](sin(\theta))[/tex]

Use the other identity to solve for the value of ([tex]sin(\theta)[/tex]) when given the value of ([tex]cos(2\theta)[/tex]).

[tex]cos(2\theta)=1-2(sin^2(\theta))[/tex]

Substitute the given information in and solve for ([tex]sin(\theta)[/tex]).

[tex]cos(2\theta)=1-2(sin^2(\theta))[/tex]

[tex]-0.4=1-2(sin^2(\theta))[/tex]

Inverse operations,

[tex]-0.4=1-2(sin^2(\theta))[/tex]

[tex]-1.4=-2(sin^2(\theta))[/tex]

[tex]0.7=sin^2(\theta)[/tex]

[tex]\sqrt{0.7}=sin(\theta)[/tex]

Since this angle is found in the third quadrant, its value is actually:

[tex]sin(\theta)=-\sqrt{0.7}[/tex]

4. Solve for [tex](tan(\theta))[/tex]

One can use the following identity to solve for [tex](tan(\theta))[/tex];

[tex]tan(\theta)=\frac{sin(\theta)}{cos(\theta)}[/tex]

Substitute the values on just solved for and simplify,

[tex]tan(\theta)=\frac{sin(\theta)}{cos(\theta)}[/tex]

[tex]tan(\theta)=\frac{-\sqrt{0.7}}{-\sqrt{0.3}}[/tex]

[tex]tan(\theta)=\frac{\sqrt{0.7}}{\sqrt{0.3}}[/tex]

[tex]tan(\theta)=\frac{\sqrt{\frac{7}{10}}}{\sqrt{\frac{3}{10}}}[/tex]

Rationalize the denominator,

[tex]tan(\theta)=\frac{\sqrt{\frac{7}{10}}}{\sqrt{\frac{3}{10}}}[/tex]

[tex]tan(\theta)=\frac{\sqrt{\frac{7}{10}}}{\sqrt{\frac{3}{10}}}*\frac{\sqrt{\frac{3}{`0}}}{\sqrt{\frac{3}{10}}}[/tex]

[tex]tan(\theta)=\frac{\sqrt{\frac{7}{10}*\frac{3}{10}}}{\sqrt{\frac{3}{10}*\frac{3}{10}}}[/tex]

[tex]tan(\theta)=\frac{\sqrt{\frac{21}{100}}}{\frac{3}{10}}[/tex]

[tex]tan(\theta)=\frac{\frac{\sqrt{21}}{10}}{\frac{3}{10}}[/tex]

[tex]tan(\theta)=\frac{\sqrt{21}}{10}*\frac{10}{3}[/tex]

[tex]tan(\theta)=\frac{\sqrt{21}}{3}[/tex]

Answer:

i have no idea that's why I need ur help

Answer:

$17.25

Step-by-step explanation:

The tip is 15% of $15.00, or 0.15 * 15 = $2.25

We add that to the meal's cost, which is $15.00

15.00 + 2.25 = 17.25

Answer:

8

Step-by-step explanation:

6x+5=53

6x=48

6x/6=48/6

x=8

Answer:

[tex]2(a + 1) \times (3a + 5)[/tex]

Step-by-step explanation:

[tex]6(a + 1 {)}^{2} + 4(a + 1)[/tex]

➡️ [tex]2(a + 1) \times (3(a + 1) + 2)[/tex]

➡️ [tex]2(a + 1) \times (3a + 3 + 2)[/tex]

➡️ [tex]2(a + 1) \times (3a + 5)[/tex]

Answer:

6  19 /24

Step-by-step explanation:

find the lcd and add

-8/10,-12/15,-16/20,-20/25,-24/30,etc.

The number sets that apply to -4/5 is the fractions.

Fractions represent the parts of a whole or collection of objects.

A fraction has two parts. The number on the top of the line is called the numerator and the number on the top of the line is called the denominator.

Now the given number is,

-4/5

-4/5 is a fraction. A fraction has two components numerator and denominator. This can positive or negative. Other example of fractions include 1/2,3/2,-5/2,-1/3.

The numbers who are not fractions are 0, 3, 6, 7.7.

Thus, the number sets that apply to -4/5 is the fractions.

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Answer:

a) 16/25

b)3/2

Step-by-step explanation:

all explaination is in picturw below

Answer:

Below.

Step-by-step explanation:

I cant draw you a picture but it will be one right triangle inside the other where the vertical tower will be one leg common to 2 triangles and the base of the 2 triangles will be x and x+10 metres.

Tan 30 = h/ (x + 10)

tan 45 = h/x        where h is the height of the tower.

From the second equation  x = h / tan45

Substituting in the first equation;

tan30 = h / (h/tan45 + 10

Tan 30 = 1/ √3 and tan 45 = 1 so

1/ 1.732 = h/ (h + 10)

0.5774 = h/(h + 10)

h = 0.5774h + 57.74

0.4226 h = 57.74

h = 136.6 m to nearest tenth.

Answer:

770

Step-by-step explanation:

12 month ×60 per month

Plus 50 set up fee

=770

Answer:

x=-3

Step-by-step explanation:

-4(-2x+5)-5x+5=-24

8x-20-5x+5=-24

3x-15=-24

3x=-9

x=-3

I hope that this helped you!

Answer:

15.1 (rounded to the nearest tenth decimal point)

Step-by-step explanation:

The explanation is, this is simple maths, nothing else. Let me know if it helps. Thank you

Answer:

Um srry I am a hack I like this app Haha I hadked this girls brainy hehehe