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3 years ago

9

Help!! NO SPAM!!!! I will mark brainliest. A phone banking password consists of 2 letters followed by 4 digits. The letters B an

d X are not used, and the last digit cannot be 0. How many different passwords are possible?

1 answer:

EleoNora [17]3 years ago

3 0

Answer: 5184000

Step-by-step explanation:

24x24x10x10x10x9

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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

3 years ago

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Heeeeeeelpppppppppppppppppp

kow [346]

The answer is c hope this helps

3 0

3 years ago

Read 2 more answers

Find the equation of a line that has a slope of 2 and passes through the point.<br> point (-7, 5)

sashaice [31]

Answer:

$\large\boxed{y-5=2(x+7)\leftarrow\text{point-slope form}}\\\boxed{y=2x+19\leftarrow\text{slope-intercept form}}$

Step-by-step explanation:

The point-slope form of an equation of a line:

$y-y_1=m(x-x_1)$

m - slope

(x₁, y₁) - point

We have the slope m = 2 and the point (-7, 5) → x₁ = -7, y₁ = 5.

Substitute:

$y-5=2(x-(-7))\\\\y-5=2(x+7)$

Convert to the slope-intercept form (y = mx + b):

$y-5=2(x+7)$ <em>use distributive property</em>

$y-5=2x+14$ <em>add 5 to both sides</em>

$y=2x+19$

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3 years ago

Evaluate the following numerical expression 2+(-3)+7

zlopas [31]

Answer:

Step-by-step explanation:

2 + (-3) + 7 = 2 - 3 + 7 = 9 - 3 = 6 <==

a positive multiplied by a negative will be negative

6 0

4 years ago

After a %25 discount, the price of the television is now $600. What was the price before the discount?

guajiro [1.7K]

You will pay $450 for a item with original price of $600 when discounted 25%. In this example, if you buy an item at $600 with 25% discount, you will pay 600 - 150 = 450 dollars.

Before- 750

___________

hope you understand! :)

- Lexi

7 0

3 years ago