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3 years ago

PLEASE HELLLLLLLLLLLLLLP ME I NEED HELP PLEASE EXPLAIN HOW TO DO IT AS I HAVE A TEST NEXT WEEK AND IM REALLY STRESSED

Mathematics

1 answer:

Fynjy0 [20]3 years ago

3 0

Answer:

C. Cos(60°) = Sin(30°)

Step-by-step explanation:

Cos(60°) = 0.5

Sin(30°) = 0.5

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9(k-4)-7k=32-2(k-8)

IrinaK [193]

Answer: k=21

Step-by-step explanation:

1. Distribute the 9 to the k and the -4 in the parentheses.

9 · k = 9k and 9 · -4 = -36

You now have 9k - 36 - 7k. You can combine the like terms of 9k and -7k and get 2k, giving you 2k - 36.

2. For the other side of the equation, you also distribute -2 to the k and -8 in the parantheses.

-2 · k = -2k and -2 · -8 = 16

You now have 32 - 2k + 16. Combine the like terms 32 and 16 (32 + 16) and you get 48. This gives you the equation 48 - 2k.

3. Now you should have the equation 2k - 36 = 48 - 2k.

You want the k on one side of the equation so you need to cancel out one of them. I cancelled out -2k by adding 2k to it. You also need to add this 2k to your 2k on the other side of the equation.

Ex: 2k - 36 = 48 - 2k

+2k +2k

4. Now you should have 4k - 36 = 48. You need to get 4k by itself so cancel out -36 from both sides by adding 36 to -36 and adding 36 to 48.

You should now have 4k = 84 (48 + 36 = 84).

Divide both sides by 4 to get k by itself. 4 divided by 4 makes k and 84 divided by 4 equals 21. This makes k = 21, which is your answer.

4 0

3 years ago

Read 2 more answers

Mr. fudge is going to roll two fair dice. what is the probability that the sum will be 4 or less?

Kay [80]

Answer:its going to be 8

Step-by-step explanation:because 4 + 4 = 8,

4 is a fair number and equal.

4 0

4 years ago

What is the circumference of circle with a diameter of 9 feet? Use 3.14 for tt

ankoles [38]

Answer:

28.26

Step-by-step explanation:

The formula for calculating diameter is π<em>d</em> (pi times the diameter), so 3.14 times 9 is 28.26.

4 0

3 years ago

Read 2 more answers

ΔA’B’C’ is a reflection of ΔABC. Which best describes the reflection?

ruslelena [56]

Answer:

A reflection over the line x=3

Step-by-step explanation:

5 0

3 years ago

A. Do some research and find a city that has experienced population growth.

horrorfan [7]

A. The city we will use is Orlando, Florida, and we are going to examine its population growth from 2000 to 2010. According to the census the population of Orlando was 192,157 in 2000 and 238,300 in 2010. To examine this population growth period, we will use the standard population growth equation $N_{t} =N _{0}e^{rt}$
where:
$N(t)$ is the population after $t$ years
$N_{0}$ is the initial population
$t$ is the time in years
$r$ is the growth rate in decimal form
$e$ is the Euler's constant
We now for our investigation that $N(t)=238300$ , $N_{0} =192157$ , and $t=10$ ; lets replace those values in our equation to find $r$ :
$238300=192157e^{10r}$
$e^{10r} = \frac{238300}{192157}$
$ln(e^{10r} )=ln( \frac{238300}{192157} )$
$r= \frac{ln( \frac{238300}{192157}) }{10}$
$r=0.022$
Now lets multiply $r$ by 100% to obtain our growth rate as a percentage:
$(0.022)(100)$ =2.2%
We just show that Orlando's population has been growing at a rate of 2.2% from 2000 to 2010. Its population increased from 192,157 to 238,300 in ten years.

B. Here we will examine the population decline of Detroit, Michigan over a period of ten years: 2000 to 2010.
Population in 2000: 951,307
Population in 2010: 713,777
We know from our investigation that $N(t)=713777$ , $N_{0} =951307$ , and $t=10$ . Just like before, lets replace those values into our equation to find $r$ :
$713777=951307e^{10r}$
$e^{10r} = \frac{713777}{951307}$
$ln(e^{10r} )=ln( \frac{713777}{951307} )$
$r= \frac{ln( \frac{713777}{951307}) }{10}$
$r=-0.029$
$(-0.029)(100)$ = -2.9%.
We just show that Detroit's population has been declining at a rate of 2.2% from 2000 to 2010. Its population increased from 192,157 to 238,300 in ten years.

C. Final equation from point A: $N(t)=192157e^{0.022t}$ .
Final equation from point B: $N(t)=951307e^{-0.029t}$
Similarities: Both have an initial population and use the same Euler's constant.
Differences: In the equation from point A the exponent is positive, which means that the function is growing; whereas, in equation from point B the exponent is negative, which means that the functions is decaying.

D. To find the year in which the population of Orlando will exceed the population of Detroit, we are going equate both equations $N(t)=192157e^{0.022t}$ and $N(t)=951307e^{-0.029t}$ and solve for t:
$192157e^{0.022t} =951307e^{-0.029t}$
$\frac{192157e^{0.022t} }{951307e^{-0.029t} } =1$
$e^{0.051t} = \frac{951307}{192157}$
$ln(e^{0.051t})=ln( \frac{951307}{192157})$
$t= \frac{ln( \frac{951307}{192157}) }{0.051}$
$t=31.36$
We can conclude that if Orlando's population keeps growing at the same rate and Detroit's keeps declining at the same rate, after 31.36 years in May of 2031 Orlando's population will surpass Detroit's population.

E. Since we know that the population of Detroit as 2000 is 951307, twice that population will be $2(951307)=1902614$ . Now we can rewrite our equation as: $N(t)=1902614e^{-0.029t}$ . The last thing we need to do is equate our Orlando's population growth equation with this new one and solve for t:
$192157e^{0.022t} =1902614e^{-0.029t}$
$\frac{192157e^{0.022t} }{1902614e^{-0.029t} } =1$
$e^{0.051t} = \frac{1902614}{192157}$
$ln(e^{0.051t} )=ln( \frac{1902614}{192157} )$
$t= \frac{ln( \frac{1902614}{192157}) }{0.051}$
$t=44.95$
We can conclude that after 45 years in 2045 the population of Orlando will exceed twice the population of Detroit.

8 0

4 years ago