Ask question

Ask question

All categories

3 years ago

5

Three friends bought 4, 6, and 8 books. The table shows the cost of the books. What is the constant of proportionality? 2 7.5 15

30

2 answers:

Svetach [21]3 years ago

6 0

Your anwser would be 8

Alexxandr [17]3 years ago

3 0

The answer is 15 because if you look at the number if books, it goes by 2. If you look at the prices, it goes by 15. What it is mainly asking for is what the number goes by. Therefore the correct answer is 15.

You might be interested in

What is the length of the hypotenuse?

torisob [31]

Step-by-step explanation:

25 is the answer . hope it helps

3 0

2 years ago

The liquid base of an ice cream has an initial temperature of 86°C before it is placed in a freezer with a constant temperature

Karolina [17]

The temperature of the ice cream 2 hours after it was placed in the freezer is 37.40 °C

From Newton's law of cooling, we have that

$T_{(t)}= T_{s}+(T_{0} - T_{s})e^{kt}$

Where

$(t) = \ time$

$T_{(t)} = \ the \ temperature \ of \ the \ body \ at \ time \ (t)$

$T_{s} = Surrounding \ temperature$

$T_{0} = Initial \ temperature \ of \ the \ body$

$k = constant$

From the question,

$T_{0} = 86 ^{o}C$

$T_{s} = -20 ^{o}C$

∴ $T_{0} - T_{s} = 86^{o}C - -20^{o}C = 86^{o}C +20^{o}C$

$T_{0} - T_{s} = 106^{o} C$

Therefore, the equation $T_{(t)}= T_{s}+(T_{0} - T_{s})e^{kt}$ becomes

$T_{(t)}=-20+106 e^{kt}$

Also, from the question

After 1 hour, the temperature of the ice-cream base has decreased to 58°C.

That is,

At time $t = 1 \ hour$ , $T_{(t)} = 58^{o}C$

Then, we can write that

$T_{(1)}=58 = -20+106 e^{k(1)}$

Then, we get

$58 = -20+106 e^{k(1)}$

Now, solve for $k$

First collect like terms

$58 +20 = 106 e^{k}$

$78 =106 e^{k}$

Then,

$e^{k} = \frac{78}{106}$

$e^{k} = 0.735849$

Now, take the natural log of both sides

$ln(e^{k}) =ln( 0.735849)$

$k = -0.30673$

This is the value of the constant $k$

Now, for the temperature of the ice cream 2 hours after it was placed in the freezer, that is, at $t = 2 \ hours$

From

$T_{(t)}=-20+106 e^{kt}$

Then

$T_{(2)}=-20+106 e^{(-0.30673 \times 2)}$

$T_{(2)}=-20+106 e^{-0.61346}$

$T_{(2)}=-20+106\times 0.5414741237$

$T_{(2)}=-20+57.396257$

$T_{(2)}=37.396257 \ ^{o}C$

$T_{(2)} \approxeq 37.40 \ ^{o}C$

Hence, the temperature of the ice cream 2 hours after it was placed in the freezer is 37.40 °C

Learn more here: brainly.com/question/11689670

6 0

1 year ago

Read 2 more answers

Please help !!!!!!!!!!!!

zhannawk [14.2K]

Answer:

25+40

Step-by-step explanation:

for the area of a triangle you multiple the base times the height. for the area of the square it is the length times width.

NOTE: to completely answer just add 25+40

6 0

2 years ago

Find The Value Of x ?

slega [8]

<u>Answer</u>:

1) $x = -1$ || 2) $x = 10$

<u>Explanation</u>:

1)

→ $\log _3\left(\frac{1}{3}\right)=x$

→ $\frac{1}{3} = 3^x$

→ $3^{-1} = 3^x$

→ $x = -1$

2)

→ $\log _3\left(x-1\right)=2$

→ $x - 1 = 3^2$

→ $x -1 = 9$

→ $x = 9 +1$

→ $x = 10$

5 0

1 year ago

Read 2 more answers

In the figure, m∠AOB = m∠COD. Which property of equality will you use to prove m∠AOC = m∠BOD?

Cerrena [4.2K]

Answer:

transitive

.......gguf

4 0

2 years ago

Read 2 more answers