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3 years ago

Simplify the following: (r+s-t)-(r-s+t)

1 answer:

4 0

R+s-t-(r-s+t)

=2s-t is the answer

People think this answer would be just =2s but I have verified with an online calculator and the answer that textbooks look for regarding this is 2s-t

You would assume you would go r-r and thats 0 so no r's

you would say s-(-s) makes it plus and theres 2s

and you would say -t -(+t) is -t

that's why the answer is 2s-t

At first I also did t-(+t) and thought it would be no t's but the answer is in fact 2s-t

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How many solutions does this equation have?<br><br> 8n = 10 + 10n

Andre45 [30]

Answer:

Step-by-step explanation:

-10n+8n=10

-2n=10

n=-5

So, one solution

5 0

2 years ago

The solution to the equation x3 = 125 is: 5 -5 ±5

AveGali [126]

Answer:

x=5

Step-by-step explanation:

x^3 = 125

Take the cubed root of each side

x^3 ^ (1/3) = 125 ^ (1/3)

x = 5

3 0

3 years ago

Which equation represents the sentence? Four more than a number is half the number.

ahrayia [7]

A. n+4=n/2

B. cannot be the answer because it is subtracting instead of adding.

C. cannot be the answer because half of the number is supposed to go after the equal sign.

D. cannot be the answer because the half of the number part did not go before adding the number. Also, it's subtracting instead of adding.

5 0

3 years ago

One year, the population of a city was 330,000. Several years later

Goshia [24]

Answer:

18% Decrease.

Step-by-step explanation:

You can use this formula for % decrease questions. :)

Decrease= Starting value (original) - Final Value (the smaller number) / starting value x 100.

Hope this helps,

Azumayay

3 0

2 years ago

Suppose that you were not given the sample mean and sample standard deviation and instead you were given a list of data for the

Troyanec [42]

Answer:

So, the sample mean is 31.3.

So, the sample standard deviation is 6.98.

Step-by-step explanation:

We have a list of data for the speeds (in miles per hour) of the 20 vehicles. So, N=20.

We calculate the sample mean :

$\mu=\frac{19 +19 +22 +24 +25 +27 +28+ 37 +35 +30+ 37+ 36+ 39+ 40+ 43+ 30+ 31+ 36+ 33+ 35}{20}\\\\\mu=\frac{626}{20}\\\\\mu=31.3$

So, the sample mean is 31.3.

We use the formula for a sample standard deviation:

$\sigma=\sqrt{\frac{1}{N-1}\sum_{i=1}^{N}(x_i-\mu)^2}$

Now, we calculate the sum

$\sum_{i=1}^{20}(x_i-31.3)^2=(19-31.3)^2+(19-31.3)^2+(22-31.3)^2+(24-31.3)^2+(25-31.3)^2+(27-31.3)^2+(28-31.3)^2+(37-31.3)^2+(35-31.3)^2+(30-31.3)^2+(37-31.3)^2+(36-31.3)^2+(39-31.3)^2+(40-31.3)^2+(43-31.3)^2+(30-31.3)^2+(31-31.3)^2+(36-31.3)^2+(33-31.3)^2+(35-31.3)^2\\\\\sum_{i=1}^{20}(x_i-31.3})^2=926.2\\$

Therefore, we get

$\sigma=\sqrt{\frac{1}{N-1}\sum_{i=1}^{N}(x_i-\mu)^2}\\\\\sigma=\sqrt{\frac{1}{19}\cdot926.2}\\\\\sigma=6.98$

So, the sample standard deviation is 6.98.

3 0

2 years ago