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3 years ago

Which statement is true? A. 2x – 1 = 13 and x = 6 B. 2x – 1 = 13 and x = 7 C. 2x + 1 = 13 and x = 7 D. 2x – 1 = 13 and x = 11

Mathematics

1 answer:

alexandr1967 [171]3 years ago

6 0

Answer:

B. 2x – 1 = 13 and x = 7

Step-by-step explanation:

We are given 4 equations and a solution for each. We have to tell which of the given solution satisfies the given equation.

Option A.

2x -1 = 13 and x = 6

Using this value in the equation, we get:

2(6) -1 = 13

12 - 1 = 13

11 = 13, which is not true. Hence this option is not valid

Option B.

2x - 1 = 13 and x = 7

Using the value in the equation, we get:

2(7) - 1 =13

14 - 1 =13

13 = 13, which is true. Hence this option is valid.

Option C.

2x + 1 =13 and x = 7

Using the value in the equation, we get:

2(7) + 1 = 13

15 = 13, which is not true. So this option is not valid

Option D.

2x - 1 = 13 and x = 11

Using this value in the equation, we get:

2(11) - 1 = 13

21 = 13, which is not true. Hence this option is not valid.

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Answer:

5/6

Step-by-step explanation:

The slope is y change over x change so...

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3 years ago

A company buys computers and printers. Each computer costs $550 and each printer costs $390. If the company spends $8160 and buy

maxonik [38]

Answer:the company bought 12 computers and 4 printers.

Step-by-step explanation:

Let x represent the number of computers that the company bought.

Let y represent the number of printers that the company bought.

The company buys a total of 16 machines. It means that

x + y = 16

Each computer costs $550 and each printer costs $390. If the company spends $8160 for all the computers and printers that was bought, it means that

550x + 390y = 8160 - - - - - - - - - - 1

Substituting x = 16 - y into equation 1, it becomes

550(16 - y) + 390y = 8160

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6 0

3 years ago

(6x – 30° and m

k0ka [10]

9514 1404 393

Answer:

48°

Step-by-step explanation:

Supplementary angles total 180°.

m∠A +m∠B = 180°

(6x -30)° +(8x +28)° = 180°

14x = 182 . . . . . . . . . . . . . . . . divide by ° and add 2

x = 13 . . . . . . . . . . . . . . . . . . . .divide by 14

Then the measure of angle A is ...

m∠A = (6·13 -30)° = 6(13 -5)° = 6·8°

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3 years ago

Todd Holland from NY grows pumpkins. He studied his past records carefully and concluded that his biggest pumpkins are distribut

ehidna [41]

Answer:

$P(X>1000)$

And the best way to solve this problem is using the normal standard distribution and the z score given by:

$z=\frac{x-\mu}{\sigma}$

If we apply this formula to our probability we got this:

$P(X>1000)=P(\frac{X-\mu}{\sigma}>\frac{1000-\mu}{\sigma})=P(Z>\frac{1000-950}{50})=P(z>1)$

And we can find this probability using the complement rule and the normal standard table and we got:

$P(z>1)=1-P(z$

Step-by-step explanation:

Previous concepts

Normal distribution, is a "probability distribution that is symmetric about the mean, showing that data near the mean are more frequent in occurrence than data far from the mean".

The Z-score is "a numerical measurement used in statistics of a value's relationship to the mean (average) of a group of values, measured in terms of standard deviations from the mean".

Solution problem

Let X the random variable that represent the variable of interest of a population, and for this case we know the distribution for X is given by:

$X \sim N(950,50)$