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2 years ago

Help pls I’ll give 50 points ! If right math ppl

Mathematics

2 answers:

mina [271]2 years ago

6 0

The answer is -15 or the last option (E)

-Hope this helps

Georgia [21]2 years ago

3 0

$f(x)=-3x$

Substitute x = 5 in the equation.

$f(5)=-3(5)\\f(5)=-15$

Therefore, the answer is -15 or last choice when x = 5.

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53% of what number is 93?

Liono4ka [1.6K]

Answer:

About 175.47

Step-by-step explanation:

*The answer is decimal*

.53*x=93

93/.53= about 175.47

6 0

2 years ago

Read 2 more answers

If a substance decays at a rate of 25% every 10 years, how long will it take 512 grams of the substance to decay to 121.5 grams

Juliette [100K]

Answer:

It will take 50 years to decay from 512 grams to 121.5 grams.

Step-by-step explanation:

The decay formula :

$N=N_0e^{-\lambda t}$

where

N= amount of substance after t time

N₀= initial of substance

t= time.

A substance decays at a rate 25% every 10 years.

So, remaining amount of the substance is = (100%-25%)= 75%

$\frac{N}{N_0}=\frac{75\%}{100\%}=\frac{75}{100}=\frac34$ , t= 10

$N=N_0e^{-\lambda t}$

$\Rightarrow \frac {N}{N_0}=e^{-\lambda t}$

$\Rightarrow \frac34 =e^{-\lambda .10}$

Taking ln both sides

$\Rightarrow ln|\frac34| =ln|e^{-\lambda .10}|$

$\Rightarrow ln|\frac34|=-10\lambda$

$\Rightarrow \lambda=\frac{ ln|\frac34|}{-10}$

Now , N₀= 512 grams, N= 121.5 grams, t=?

$N=N_0e^{-\lambda t}$

$\therefore 121.5=512e^{-\frac{ln|\frac34|}{-10}.t}$

$\Rightarrow 121.5=512e^{\frac{ln|\frac34|}{10}.t}$

$\Rightarrow \frac{121.5}{512}=e^{\frac{ln|\frac34|}{10}.t}$

Taking ln both sides

$\Rightarrow ln|\frac{121.5}{512}|=ln|e^{\frac{ln|\frac34|}{10}.t}|$

$\Rightarrow ln|\frac{121.5}{512}|={\frac{ln|\frac34|}{10}.t}$

$\Rightarrow t=\frac{ln|\frac{121.5}{512}|}{\frac{ln|\frac34|}{10}}$

$\Rightarrow t=\frac{10.ln|\frac{121.5}{512}|}{{ln|\frac34|}}$

⇒t=50 years

It will take 50 years to decay from 512 grams to 121.5 grams.

8 0

2 years ago

6 times the sum of a number t and 5 is s

podryga [215]

Do you have any multiple choice questions? because I would need some choices so i could help you answer the question.

8 0

2 years ago

The area of a circle is 8π square units. What is the radius of the circle in simplest radical form?

Sav [38]

Answer:

Step-by-step explanation:

The area of a circle is :A= π r² r : the radius

A= 8π square units

so : π r² = 8π

r² = 8

r = √8 = √(4 × 2) =√4×√2

r = 2√2 units

8 0

2 years ago

Create a data set describing two variables, with at least five data points, that has an equation for the line of best fit of y =

Ira Lisetskai [31]

Answer:

X = 2, 4, 6, 7, 9

Y = 29, 33, 37, 39, 43

Step-by-step explanation:

Given a best fit line of :

y = 2x + 25

Take points X as :

X = 2, 4, 6, 7, 9

X = 2

y = 2(2) + 25 = 4 + 25 = 29

X = 4

y = 2(4) + 25 = 8 + 25 = 33

X = 6

y = 2(6) + 25 = 12 + 25 = 37

X = 7

y = 2(7) + 25 = 14 + 25 = 39

X = 9

y = 2(9) + 25 = 18 + 25 = 43

5 0

2 years ago