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3 years ago

Which property was used to simplify the expression? 3c+ 9 + 4c = 3c + 4c + 9

2 answers:

5 0

The change that happened from the first half of the equation to the second half was you moved the 9 and the 4c around.
Commutative property of addition allows you to do that. It's what says that 2+3 is the same thing as 3+2

TEA [102]3 years ago

3 0

B.

Commutative, root word is commute- to move around. a+b+c = c+a+b
Associative deals with group (a+b)+c = (a+c)+b.
Both of these pertain to only addition and multiplication.

Distributive means to distribute the number outside of the parentheses to the numbers inside by multiplication or division. Only if the numbers inside are being added or subtracted

Inverse- Additive- equals zero. 2+(-2)=0
Multiplicative- equals one. 9 * (1/9)=1

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What is one ninth plus two thirds simplified

GREYUIT [131]

7/9. 1/9 plus 2/3. You have to get the lest common denominator, so change 3 to 9 by multiplying it by three. Remember, you have to do the same thing you do to the denominator to the numerator. So, 2/3 would be 6/9. 6/9 plus 1/9 is easy, basic facts. 1 and 6 is 7, and you put the nine under. You get 7/9

4 0

3 years ago

Read 2 more answers

A taxi cab in myrtle beach charges $2 per mile and $1 for every person. If a taxi cab ride for two people costs $12, how far did

oksian1 [2.3K]

Answer:

5 Miles

Step-by-step explanation:

5 Miles = 1 Miles = $2 X 5 = $10

1 Person = $1

Therefore 2 People = $1 X 2

7 0

3 years ago

An automobile company wants to determine the average amount of time it takes a machine to assemble a car. A sample of 40 times y

aksik [14]

Answer:

A 98% confidence interval for the mean assembly time is [21.34, 26.49] .

Step-by-step explanation:

We are given that a sample of 40 times yielded an average time of 23.92 minutes, with a sample standard deviation of 6.72 minutes.

Firstly, the pivotal quantity for finding the confidence interval for the population mean is given by;

P.Q. = $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ ~ $t_n_-_1$

where, $\bar X$ = sample average time = 23.92 minutes

s = sample standard deviation = 6.72 minutes

n = sample of times = 40

$\mu$ = population mean assembly time

Here for constructing a 98% confidence interval we have used a One-sample t-test statistics because we don't know about population standard deviation.

So, a 98% confidence interval for the population mean, $\mu$ is;

P(-2.426 < $t_3_9$ < 2.426) = 0.98 {As the critical value of z at 1% level

of significance are -2.426 & 2.426}

P(-2.426 < $\frac{\bar X-\mu}{\frac{s}{\sqrt{n} } }$ < 2.426) = 0.98

P( $-2.426 \times {\frac{s}{\sqrt{n} } }$ < ${\bar X-\mu}$ < $2.426 \times {\frac{s}{\sqrt{n} } }$ ) = 0.98

P( $\bar X-2.426 \times {\frac{s}{\sqrt{n} } }$ < $\mu$ < $\bar X+2.426 \times {\frac{s}{\sqrt{n} } }$ ) = 0.98

98% confidence interval for $\mu$ = [ $\bar X-2.426 \times {\frac{s}{\sqrt{n} } }$ , $\bar X+2.426 \times {\frac{s}{\sqrt{n} } }$ ]

= [ $23.92-2.426 \times {\frac{6.72}{\sqrt{40} } }$ , $23.92+2.426 \times {\frac{6.72}{\sqrt{40} } }$ ]

= [21.34, 26.49]

Therefore, a 98% confidence interval for the mean assembly time is [21.34, 26.49] .

7 0

2 years ago

A model car is 3 3/4 inches long.using a scale of 1/2 inch=2 feet,find the actual length of the car

MaRussiya [10]

Answer:

14.25 because for every 1/2 inch, the car is 2 feet.

Step-by-step explanation:

8 0

3 years ago

Gala2k [10]

Answer:

The Answer is C.

Step-by-step explanation:

There is only one number before the decimal point, 6. 6 ones, so we already cross out A and D as incorrect. Now we have B and C. There is only two numbers after the decimal point. The first number after the point is in the tenths place. So, B is the correct answer.

Make me brainlyest if correct, you're welcome!

6 0

2 years ago