Why does no one answer my questions in Brainly? If you're good at math, please look at my recent questions and answer them if you know it. Now, below is one of the questions that I am struggling with. Please help!

Answer:

(n - 1)/2

Step-by-step explanation:

F = (1 - 1/n) + (1 - 2/n) + (1 - 3/n) + ...(1 - n/n)

  = (1 + 1 ... + 1) - (1/n + 2/n + 3/n + ...n/n)

     (there are n terms of 1)

  = n - (1 + 2 + 3 + ... + n)/n

  = n - [n x (n + 1)/2]/n

  = n - [n x (n + 1)]/[2 x n]

  = n - (n+1)/2

  = (2n - n - 1)/2

  = (n - 1)/2

Hope this helps!

Answer:

Step-by-step explanation:

The way you can solve this is by splitting the cube into two parts.

Split the top cube apart from the bottom cube and then find the volume of each and add them together.

The first cube on top would be 80x90x75= 540000 centimeters

The second cube would be 270x75x80=1620000 centimeters

540000+1620000=2160000 centimeters

Hope this help!

Comment if you would like a visual drawing of the math!!

(Also the answer can be written as 21600 meters)

Answer:

is greater than

Step-by-step explanation:

The answer is C less than we got it wrong

Step-by-step explanation:

Answer:

1. Triangular prism

2. Trapezoidal prism

3. Pentagonal prism

4. Hexagonal prism

Answer:

Yes, both are one third of the other number

Step-by-step explanation:

Fractions are determined to be equivalent by multiplying the numerator and denominator of one fraction by the same number.

// have a great day //

Answer:

-1

Step-by-step explanation:

write it in the following manner:

-3x + 7  - 5x = 15

-8x + 7 = 15

-8x = 8

x = -1

Thus, the number has to be smaller than -1.

The smallest integer that makes the given inequality true is 0.

Linear inequalities are defined as those expressions which are connected by inequality signs like >, <, ≤, ≥ and ≠ and the value of the exponent of the variable is 1.

Given inequality,

-3x + 7 - 5x < 15

We have to find the value of x.

(-3x - 5x) + 7 < 15

-8x < 8

Dividing whole sides by -1, the inequality sign changes.

x > -1

Smallest possible value is 0.

Hence the smallest posible value is 0.

Learn more about Inequalities here :

https://brainly.com/question/26855203

#SPJ2

Answer:

1342 feet

Step-by-step explanation:

Kimmy's house is located at (8, 4)

The school entrance is located at (-4, -2).

To find the distance Kimmy walks to school every day, we use the Distance formula:

[tex]\text{Distance =}\sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

Where [tex](x_1,y_1)=(8, 4),$ and (x_2,y_2)=(-4, -2).[/tex]

[tex]\text{Distance=}\sqrt{(-4-8)^2+(-2-4)^2}\\=\sqrt{(-12)^2+(-6)^2}\\=\sqrt{144+36}\\=\sqrt{180} \\=13.42$ Units\\Since 1 coordinate unit represents 100 feet.\\\\Distance walked by Kimmy to school every day\\=13.42*100 feet\\=1342 feet (to the nearest foot)[/tex]

Answer:

-4

Step-by-step explanation:

→Distribute the -1 to (x - 1):

(x - 5) - (x - 1)

x - 5 - x + 1

→Add like terms (x and -x, -5 and 1):

-4

Answer:

-4

Step-by-step explanation:

(x-5)-(x-1)

x-5-x+1

x-x-5+1 = -4

Answer:

Anna spent $51 in all.

Step-by-step explanation:

36+15=51

Answer:

$51

Step-by-step explanation:

Anna bought two items: a backpack and a lunch box. If we want to find the total amount of money Anna spent, we have to add the price of the backpack and the price of the lunchbox.

price of backpack+price of lunchbox

The backpack cost $36 and the lunchbox cost $15

$36+$15

Add 36 and 14

$51

Anna spent $51 in total

Answer:

240g of cocoa

Step-by-step explanation:

96/24 = 4 times as many brownies, 4 times as many ingredients needed. To find the amount of cocoa, multiply the original amount by four to get 60g × 4 = 240g.

Answer: 6:9

Just divide  saturatedfats/TotalFats=6/9

Step-by-step explanation:

Answer:

Function, passes the vertical line test

Step-by-step explanation:

The graph is a function.  The points have a one to one correspondences as demonstrated by the vertical line test.  Since only one point on the graph  is  touching a vertical line  at a time, it will pass the vertical line test

Answer:

3

Step-by-step explanation:

These are similar triangle

We can use ratios to solve

12         12+4

------ = ----------

9         9+DC

Using cross products

12( 9+DC) = 9*(12+4)

12 (9+DC) = 9*16

Divide each side by 12

12/12 (9+DC) = 9*16/12

9+DC = 12

Subtract 9 from each side

9+DC-9 =12-9

DC =3

Answer:

3 units

Step-by-step explanation:

We can see that triangle ADE is similar to triangle ACB.

Therefore the ratios of the lengths of their sides must be equal.

We can write AD/AC = AE/AB

we are given AD = 9, AE = 12 and AB = 12 + 4 = 16

Substituting the above values into the equation:

AD/AC = AE/AB

9 / AC = 12/16  (rearranging)

(AC)(12) = (9)(16)

AC = (9)(16)/12

AC = 12

We can also see that

DC = AC - AD

DC = 12 - 9

DC = 3 units

Answer: 14

Step-by-step explanation: chau's height = x

x * 5 =70

5x = 70

x = 70/5

x = 14

Answer:

The output value is 4

Step-by-step explanation:

The output value is the y value, so y=3(1)+1

y=3+1

y=4

The answer is D. x = 32 and x = 0

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

Explanation:

Think of x-16 as y. In other words, let y = x-16

We have (x-16)^2 = 256 become y^2 = 256.

Solve for y to get y = 16 or y = -16. You apply the square root to both sides. Don't forget about the plus/minus. This is because (-16)^2 = (-16)*(-16) = 256. We square the negative as well.

--------

If y = 16, then y = x-16 solves for x to get

y = x-16

16 = x-16

x-16 = 16

x = 16+16

x = 32 is one solution

---------

Plug in y = -16 and isolate x

y = x-16

x-16 = y

x-16 = -16

x = -16+16

x = 0 is the other solution

----------

We can check each answer by plugging them back into the original equation

Let's try x = 0

(x-16)^2 = 256

(0-16)^2 = 256

(-16)^2 = 256

256 = 256 ... works

Now try x = 32

(x-16)^2 = 256

(32-16)^2 = 256

(16)^2 = 256

256 = 256 ... also works; both answers have been confirmed

Answer:

-1/2x<-12

Multiply through by 2

-x < -24

Multiply through by -1

x > 24

Hope this helps.

Answer:

20 feet

Step-by-step explanation:

Since the term -(x-7)^2 is negative, the largest height that the ball can reach is when this term is 0. 0+20=20, meaning that the highest the ball can go is 20 feet. Hope this helps!

Answer:  20 feet

Step-by-step explanation:

The vertex form of a quadratic equation is: y = a(x - h)² + k

where (h, k) is the vertex

h is the axis of symmetry (time at which maximum height is reached)

k is the maximum height

Given: y = -(x - 7)² + 20

--> h = 7, k = 20

therefore, the maximum height of the ball is 20

Answer:

[tex]\fbox{\begin{minipage}{4em}x = -4\end{minipage}}[/tex]

Step-by-step explanation:

Given:

Equation:  [tex]4x - 1 = 3x - 5[/tex]

Solve for:

[tex]x[/tex]

Solution:

Step 1: Select relevant approach:

Let's move all the components containing x to the left side and other components to the right side (notice the change of sign of each one from positive to negative and negative to positive), then solve for [tex]x[/tex]

Step 2: Perform the calculation:

       [tex]4x - 1 = 3x - 5[/tex]

Moving components:

<=>  [tex]4x - 3x = 1 - 5[/tex]

Performing simplification to get [tex]x[/tex]

<=>[tex]x = -4[/tex]

Hope this helps!

:)

Answer:

108m^2

Step-by-step explanation:

surface area of any shape: sum of the area of its sides.

area of cross section x 2 = 4 x 3 12 m^2

area of slope:  5m x 8m = 40m^2

area of base: 8 X 3 = 24 m^2

area of back: 8m x 4m = 32m^2

sum = surface area = 108m^2

Please mark brainiest

Answer:

a) The line will be y = 15x + 99 because the 99 is a one time purchase.

b) After 1 year, x will be 12 so Muscular Marty will pay 15 * 12 + 99 = $279.

Answer:

a) y = 99 + 15x

b) 279

Step-by-step explanation:

b) 1 yr = 12 months

thus x is 12

y = 99 + 15(12) = 99 + 180 = 279

Answer:

Solution,

[tex]9y + 6 + 2(5 + y) \\ = 9y + 6 + 10 + 2y \\ combine \: like \: terms \\ = 9y + 2y + 6 + 10 \\ simplify \\ = 11y + 16[/tex]

hope this helps...

Good luck on your assignment..

Answer:

11y+16

Step-by-step explanation:

9y+6+2(5+y)=

9y+6+10+2y=

Combine like terms

11y+6+10=

11y+16

Answer:

2160

Step-by-step explanation:

1872(volume of the cube)+288(volume of the square pyramid)=

2160

v of cube= lwh

v of square pyramid= a² times h/3

please mark brainliest!

Answer:

6th term = 11

1st term = 1

d = 11 - 1/5 = 2

Answer:

3 strain would still alive after 48 hours

Step-by-step explanation:

Initial population of virus = 40000 grams

A certain virus is dying off at a rate of 18% per hour.

We are supposed to find  how much of the  strain would still be alive after 48 hours

Formula : [tex]N(t)=N_0(1-r)^t[/tex]

[tex]N_0[/tex]=Initial population

N(t)= Population after t hours

r = rate of decrease = 18% = 0.18

t = time = 48 hours

So,the  strain would still be alive after 48 hours=[tex]40000(1-0.18)^{48}=2.91 \sim 3[/tex]

Hence 3 strain would still alive after 48 hours

Answer:7

Step-by-step explanation:

7^2 = 49 (or square root of 49 is 7)

8^2 = 64 (or square root of 64 is 8)

Answer:

The answer is "70°"

Step-by-step explanation:

In the given question an attachment file is missing. so, the attachment file and its solution can be defined as follows:  

Given:

ABC is the right triangle.

Find B=?

Solution:

[tex]\Rightarrow \sin \theta= \frac{p}{h}\\\\[/tex]

[tex]\Rightarrow \sin B^{\circ}=\frac{AB}{AC}= \frac{4.8}{5.1}\\\\[/tex]

[tex]\Rightarrow \sin B^{\circ}= .941[/tex]

[tex]\Rightarrow B^{\circ}= \sin^{-1} (0.941)\\\\\bold{\sin^{-1} (0.941) = 70.2^{\circ}}\\\\\therefore \ \ \ \ \bold{B^{\circ} = 70^{\circ}}[/tex]

Answer:

70

Step-by-step explanation:

Answer:

m=-2

Step-by-step explanation:

8-(m-3)=7-3m

8-1(m)-1(-3)=7-3m

8-m+3=7-3m

-m+3m+8+3=7-3m+3m

2m+8+3=7

2m+11=7

2m=-4

m=-2

Hope this helps!

Step-by-step explanation:

So, this is how you do it.

Answer:

Linear. While all linear equations produce straight lines when graphed, not all linear equations produce linear functions. In order to be a linear function, a graph must be both linear (a straight line) and a function (matching each x-value to only one y-value).