How do you add these two consecutive triangular numbers?
TR(4)+TR(3)

Answers

Answer 1

The n-th trianglar number is given by

[tex]T_n = \dfrac{n(n+1)}2[/tex]

Then

[tex]T_4 + T_3 = \dfrac{4\times5}2 + \dfrac{3\times4}2 = \boxed{16}[/tex]

Alternatively, the triangular numbers are defined recursively by

[tex]\begin{cases}T_1 = 1 \\ T_n = T_{n-1} + n & \text{for } n>1\end{cases}[/tex]

This means

[tex]T_1=1[/tex]

[tex]T_2 = T_1 + 2 = 3[/tex]

[tex]T_3 = T_2 + 3 = 6[/tex]

[tex]T_4 = T_3 + 4 = 10[/tex]

so that

[tex]T_3+T_4=\boxed{16}[/tex]


Related Questions

What is 8,-6 over the x-axis 90 degrees

Answers

Answer:

(6,8)

Step-by-step explanation:

The rule for 90 degree rotation is (x,y)=(-y,x)

So the answer is (6,8)

Use three different values of n to demonstrate that 2 n + 3 n is equivalent to 5 n .

Answers

Answer:

2n + 3n equals to 5n in the end, so just set n equal to literally any number :)

Step-by-step explanation:

Example:

Let n = 1000

2(1000) + 3(1000) = 5(1000)

5000 = 500

Basically, plug in the number and solve on both sides each time. You will know you've demonstrated it if it's equal on both sides

Answer:

2n + 3n equals to 5n in the end, so just set n equal to literally any number

Step-by-step explanation:

Example:

Let n = 1000

2(1000) + 3(1000) = 5(1000)

5000 = 500

Basically, plug in the number and solve on both sides each time. You will know you've demonstrated it if it's equal on both sides

Each exterior angle of a regular decagon has a measure of (3x + 6)°. What is the value of x?

Answers

The answer is equal to 10

Need help as asap emergency

Answers

Answer:

$1346.4

Step-by-step explanation:

First find the rectangle portions area with lxwxh, which is 8x6x8. That equalls 384.

Then find the triangles, which is bxh, which is 6x8. That equals 144.

Add those two to get 528.

Then multiply the total area by 2.55 which will get you 1346.4

[tex]\bold{ANSWER:}[/tex]
$1346.4

[tex]\bold{SOLUTION:}[/tex]

Which function is increasing?

Answers

The answer is b………..

Which the is the correct answer?

Answers

To solve this problem, we need to use combination which is statistical tool to determine the number of ways an event may occur. The combination to select a 5 a side team from 12 students is 792.

Combination

This a mathematical technique that is used to determine the number of possible arrangements in a collection of items where the way they're arranged does not matter.

Data;

Number of Students = 12Team = 5

The combination for this would be

[tex]C = ^1^2C_5 = 792[/tex]

The combination to select a 5 a side team from 12 students is 792.

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Please help giving 80 points
Graph the function on the coordinate plain

A)what are the x intercepts
B)what is the y intercepts
C)what is the maximum and minimum value

Answers

Answer:

X Intercepts: (2, 0), (-6, 0),

Y Intercepts: (0, – 12)

minimum: (-2,-16)

Step-by-step explanation:

A) what are the x intercepts

X- axis interception points of x²+ 4x– 12:

(2,0), (-6,0)

B)what is the y intercepts

Y-axis interception point of x² + 4X – 12:

(0, – 12)

X Intercepts: (2, 0), (-6, 0), Y Intercepts: (0, – 12)

C)what is the maximum and minimum value

Parabola equation in polynomial form

The parabola params are:

a=1, b=4,c= -12

xv= -b/2a

xv= -4/2.1

simplify

xv=-2

Plug in xv = -2 to find the yv value

yv= -16

Therefore the parabola vertex is (-2, – 16)

If a<0. then the vertex is a maximum value

If a>0. then the vertex is a minimum value

a=1

minimum=(-2,-16)

A box has a width of 5 centimeters and a height of 6 centimeters. If the volume is 150 cubic centimeters, what is the length of the box?

A) 5 centimeters

B) 4 centimeters

C) 7 centimeters

D) 3 centimeters

Answers

Answer: A. 5

Step-by-step explanation:

Answer:

A)  5 cm.

Step-by-step explanation:

Volume = length * width * height

150 = length * 5 * 6

Length = 150 / (5*6)

= 150/30

= 5.

will give brainliest!!! Help pls!

Answers

Answer:

I notice that square 3 plus square 2 equals square 1, the biggest square. That must mean that the third square, squared, plus the second square, squared, equals the biggest square, squared, which is square c.

26. Each weekday, 3,200,000 people in Massachusetts
commute to work. Of the total commuters, 403,200 take
public transportation. What percentage of commuters take
public transportation?

Answers

Answer: 12.6%

Step-by-step explanation:

403,200/3,200,000 = 0.126

0.126 = 12.6%

Belle runs 16 times around a track that measures 1/4 mile long.

What fraction shows the distance that Belle runs?

How many whole miles does Belle run?

Answers

16/4 which could be simplified to be the whole number 4

1.4x10 -2 in standard form

Answers

Answer:

12

Step-by-step explanation:

1.4x10 is moving the decimal point one spot to the left, so it would be 14., which is just simply 14. Finally, 14-2=12 which is the answer.

HELP PELASE ILL MARK BRAINLIEST AND POINTS!

Answers

[tex]\qquad\qquad\huge\underline{{\sf Answer}}[/tex]

Both the given lines in graph intersect at point (5 , -2), the point must satisfy both the equations.

and if we check the options, we will observe that D. option has both the equations that satisfy the given conditions.

that is ~

[tex]\qquad \sf  \dashrightarrow \: x + y = 3[/tex]

put y = - 2,we will get :

[tex]\qquad \sf  \dashrightarrow \: x - 2 = 3[/tex]

[tex]\qquad \sf  \dashrightarrow \: x = 5[/tex]

so, 1st equation satifys the condition. let's check out 2nd one.

[tex]\qquad \sf  \dashrightarrow \: x + 2y = 1[/tex]

put y = -2

[tex]\qquad \sf  \dashrightarrow \: x + (2 \times - 2) = 1[/tex]

[tex]\qquad \sf  \dashrightarrow \: x - 4 = 1[/tex]

[tex]\qquad \sf  \dashrightarrow \: x = 5[/tex]

Hence, we can conclude that the Correct choice is D

Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar. David invested $230 in a savings account that offers a 3% return on the investment. The value of David's investment will be at least $415 after a period of years. Hint: Use the formula A = P(1 + r)t, where A is the amount after t years, P is the amount invested, r is the rate of interest, and t is the time period. Use a calculator to compute the answer, and round it off to the nearest year.

Answers

The value of David's investment will be at least $415 after a period of 20 years

Compound interest

The formula for calculating the compound interest is expressed as:

A = p(1+r)^t

Given the following parameters

A = $415P = $230r = 3% = 0.03

Substitute

415 = 230(1+0.03)^t
415/230 = 1.03^t
1.8043 = 1.03^t
t = ln(1.8043)/ln1.03

t = 20 years

The value of David's investment will be at least $415 after a period of 20 years

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PLEASE HELP WILL GIVE BRAINLEST! What is the amplitude of the function graphed below?

Answers

Answer:

[tex]2\pi[/tex]

That's it

The graphs of f(x) and g(x) are shown below:

If f(x) = (x + 7)2, which of the following is g(x) based on the translation?

g(x) = (x + 9)2
g(x) = (x + 5)2
g(x) = (x − 9)2
g(x) = (x − 5)2

Answers

Answer:

A. g(x)=(x+9)^2

Step-by-step explanation:

if it’s plus inside the parentheses it’s goes left and if it’s - it’s right

Hope this helps! ;-)

What are the domain and range of f (x) = log (x minus 1) + 2?
domain: x > 1; range: y > 2
domain: x > 1; range: all real numbers
domain: all real numbers; range: y > 1
domain: all real numbers; range: all real numbers

Answers

Answer:

domain: x > 1; range: all real numbers

Step-by-step explanation:

Given function:    [tex]f(x)=\log(x-1)+2[/tex]

Logarithms are not defined for zero or negative numbers.

[tex]\implies (x-1) > 0 \implies x > 1[/tex]

Therefore:

domain (input values):  [tex]x > 1[/tex]range (output values):  all real numbers

Answer:

B on edge

Step-by-step explanation:

Just took the test :)

Which is the completely factored form of 12x4 39x3 9x2? 3x2(x – 3)(4x – 1) 3x2(x 3)(4x 1) 3x(x 3)(4x 1) 3x(x – 3)(4x 1)

Answers

The completely factored expression of 12x⁴ + 39x³ + 9x² is 3x²(4x + 1)(x + 3)

How to factor the expression?

The polynomial expression is given as;

12x⁴ + 39x³ + 9x²

Factor out 3x² from the expression

3x²(4x² + 13x + 3)

Expand

3x²(4x² + 12x + x + 3)

Factorize the expression

3x² * 4x(x + 3) + 1(x + 3)

Factor out x + 3

3x²(4x + 1)(x + 3)

Hence, the completely factored expression of 12x⁴ + 39x³ + 9x² is 3x²(4x + 1)(x + 3)

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Solve for the variable and give an exact answer.

Answers

Answer:

4√ 2

Step-by-step explanation:

2x^2=64 and  x^2 = 32 so x= 4√ 2

What is the slope of the line shown below?

A. -1/3
B. 1/3
C. 3
D. -3

Answers

Answer:

C. 3

Step-by-step explanation:

Using the slope formula

Answer:

C. 3

Step-by-step explanation:

8 - 2/ 4 - 2 = 6/2 = 3

...................................................

What is 1/4 of 12? I can’t figure it out.

Answers

Answer:

3

Step-by-step explanation:

1/4 of 12 means (1/4) x 12

=> (1/4)x12

=> 12/4

=>  3

Answer: Heyaa! ~

Your Answer would be 3!

Step-by-step explanation:

We can write 1/4 of 12 as 1/4 × 12

To multiply fractions, follow the given steps:

Multiply the numerators.

Multiply the denominators.

Reduce the resultant fraction to its lowest terms.

Now,

1/4 × 12 = (1 × 12) / 4 = 12/4 = 3

Meaning the answer is.. 1/4 of 12 = 3

Hopefully this helps you!

PLS help

Jaime rode her bike 5 miles north to the park to meet a friend. Then they rode east to the library. If Jaime's house is 13 miles from the library, about how far is the library from the park?

Answers

please

that is the solution

Answer:8 miles

Step-by-step explanation:

What is the horizontal asymptote of j (x) = startfraction 14 x cubed 45 over 2 x cubed x 9 endfraction y = 1 y = 5 y = 7 y = 12

Answers

The horizontal asymptotes the the point where the horizontal line cutes the y-axis. The horizontal asymptotes of the function is y =7

Horizontal asymptotes of a function

The horizontal asymptotes the the point where the horizontal line cutes the y-axis,

Given the function

j(x) = 14x³+45/2x³+9

Since the powers of both numerator and denominator is the same, we will take the ratio of their coefficient as shown

y = 14/2

y = 7

Hence the horizontal asymptotes of the function is y =7

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Find the prime factorization of 945

Answers

Answer:

3 × 3 × 3 × 5 × 7

Please help quick 30 points
Evaluate 5 x + (-2 x2 ) for x = 3.

Answers

Answer:

I'd say 11 but could also be 30

A cooler is filled with different juices. There are 6 bottles of juice:
1 orange juice, 2 apple juice, 2 cranberry juice, and 1 grape juice.
What is the probability of randomly choosing 1 orange juice and then 1 apple juice
without replacing the first juice?

Answers

Answer:

1/15

Step-by-step explanation:

Total = 6 bottles

1 orange and apple

Without replacement:

P(orange and apple) = 1/6 x 1/5 = 1/15

Answer: Probability = 1/15

A is directly proportional to B.
When A = 12, B = 3
Find the value of A when B=5

Answers

Answer:

a= 20

Step-by-step explanation:

12/3

a/5

60 = 3a

a = 60/3 = 20

I am a bit confused on how to solve it so please explain ​

Answers

Answer:

Step-by-step explanation:

You could do it either way, but I have attached an image with one way to do it.

Then, using the exterior angle theorem, you can do:

(180-4x) + 100 = 3x

280 - 4x = 3x

280 = 7x

x = 40

From there, don't forget to plug in the numbers if you need to do so :)

complete the statement, and find the value of x in the diagram.
help please!

Answers

kite, x = 3. since that really long line is an angle bisector bc it’s a kite, then the two x angles should be equal to each other

Answer:

Also the quadrilateral shown is a rhombus

Step-by-step explanation:

IF COREY HAD 100 TOKENS AND HE GIVES SOME TO HIS FRIENDS! HE HAS 4 LEFT OVER! HOW MANY DID HE GIVE EACH OF HIS FRIENDS!?

Answers

Answer:

he gave away 96 but depends how many friends he gave them to.

Step-by-step explanation:

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