Ask question

Ask question

All categories

3 years ago

7

The Grade 8 Students had an end of the year dance. The DJ (disc jockey) they hired charged a flat rate (it is only charged once)

of $80, plus $2 for each student who attended the dance. The DJ was paid $196. How many students attended the dance?
a. Write an Equation you can use to solve the problem.

b. Solve your equation

c. Substitute to make sure you are correct

1 answer:

Margarita [4]3 years ago

6 0

Answer:

224

Step-by-step explanation:

Because if you add 80+2+196 you get 224

You might be interested in

9. A rectangle has a width that is 2 feet longer than four times the length. What is the length of the rectangle

Bad White [126]

Answer:

6 feet

Step-by-step explanation:

Perimeter = 2L + 2W

Since you know the perimeter is 64 feet, you would plug that into the perimeter side.

64 = 2L + 2W

You also know the width is 2 feet longer than 4 times the length.

64 = 2L + 2(2 + 4L) ----> Multiply 2 * 2 and 2 * 4l

64 = 2L + 4 + 8L ----> Subtract 4 from each side

-4 -4

60 = 2L + 8l ----> add these two

60 = 10L

/10 /10 -----> divide by 10 on each side

6 = L

Now that we know the length, find the width.

64 = 2(6) + 2(2 + 4(6)) -----> multiply 2 * 6 and 4 * 6

64 = 12 + 2(2 + 24) -------> add 24 and 2

64 = 12 + 2(26) -------> multiply 2 and 26

Before you go any further, you now know that the width is 26 feet. Continue solving.

64 = 12 + 52

64 = 64

Everything checks out.

The length is 6 feet and the width is 26 feet.

3 0

3 years ago

A rectangular storage container with an open top is to have a volume of 10 m3 . then length of its base is twice the width. mate

katrin [286]

Answer:

The cost of materials for the cheapest such container is $163.54.

Step-by-step explanation:

A rectangular storage container with an open top is to have a volume of 10 m³.

The volume of the rectangle is

$\text{Volume} =\text{Length} \times \text{Width} \times \text{Height}$

Length of its base is twice the width.

Let Width be 'w'.

Length is l=2w.

Height be 'h'.

$10 =2w\times w\times h$

$10=2w^2h$

The height in terms of width is represented as,

$h=\frac{10}{2w^2}$

$h=\frac{5}{w^2}$

According to question,

The cost is 10 times the area of the base and 6 times the total area of the sides.

i.e. Cost is given by,

$C=10(L\times W)+6(2\times L\times H+2\times W\times H)$

$C=10(2w\times w)+6(2\times 2w\times \frac{5}{w^2}+2\times w\times \frac{5}{w^2})$

$C=20w^2+\frac{120}{w}+\frac{60}{w}$

$C(w)=20w^2+\frac{180}{w}$

To get the minimum value,

Differentiate the cost w.r.t 'w',

$C'(w)=20\frac{d(w^2)}{dw}+180\frac{d(w^{-1})}{dw}$

$C'(w)=20\times 2w-180 w^{-2}$

$C'(w)=40w-\frac{180}{w^2}$

To find critical points put derivate =0,

$40w-\frac{180}{w^2}=0$

$40w=\frac{180}{w^2}$

$w^3=\frac{180}{40}$

$w=\sqrt[3]{4.5}$

$w=1.65$

We find the second derivative to minimize,

$C''(w)=40\frac{d(w)}{dw}-180\frac{d(w^{-2})}{dw}$

$C''(w)=40+360(w^{-3})$

$C''(w)>0$

As $C''(w)>0$ it is the minimum cost.

The cost is minimum at w=1.65.

Substitute the values in the cost function,

$C(1.65)=20(1.65)^2+\frac{180}{1.65}$

$C(1.65)=54.45+109.09$

$C(1.65)=163.54$

Therefore, the cost of materials for the cheapest such container is $163.54.

7 0

3 years ago

A sound wave has a frequency of 125 Hz and a speed 5000 m/s What is the wavelength of the wave

kipiarov [429]

The wave length of the sound with parameters frequency of 125 Hz and a speed 5000 m/s is 40 meters

<h3>Given Data</h3>

velocity = 5000 m/s

frequency = 125 Hz

wavelength = ??

We know that the relationship between speed, frequency and wavelength is given as

v = fλ ----------------------------1

substitute our given parameters

5000 = 125 * λ

Divide both sides by 125

λ = 5000/125

λ = 40 m

Hence the wave length of the sound is 40 meters

Learn more about sound here:

brainly.com/question/24544245

5 0

3 years ago

Which function is shown on the graph?

LenaWriter [7]

Answer:

A

Step-by-step explanation:

7 0

3 years ago

There are 15 pieces of fruit of bowl and six our apples what percent are apples.

Vinil7 [7]

40% is the answer because 6/15 = 0.4

3 0

4 years ago

Read 2 more answers