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3 years ago

Someone please urgently help me with these two short worded questions! Thanks so much

Mathematics

1 answer:

ahrayia [7]3 years ago

8 0

Answer:

6. 7x + 3 = 3x; x = -3/4

7. x - 5 = 3x - 9; x = 2

Step-by-step explanation:

6. 7x + 3 = 3x

Subtract 3x from both sides.

7x + 3 - 3x = 3x - 3x

4x + 3 = 0

Subtract 3 from both sides.

4x + 3 - 3 = 0 - 3

4x = -3

Divide both sides by 4.

x = -3/4

7. x - 5 = 3x - 9

Subtract x from both sides.

x - 5 - x = 3x - 9 - x

-5 = 2x - 9

Add 9 to both sides.

-5 + 9 = 2x - 9 + 9

4 = 2x

Divide both sides by 2.

4/2 = (2/2) x

2 = x

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a web music store offers two version of a popular song. the size of the standard version is 2.9 megabytes (MB). the size of the

miv72 [106K]

Answer: 260 downloads of the standard version were there.

Step-by-step explanation:

Let x represent the number of downloads of the standard version.

Let y represent the number of downloads of the high-quality version.

Yesterday, the high-quality version downloaded four times as often as the standard version. It means that

y = 4x

The size of the standard version is 2.9 megabytes (MB). the size of the high-quality version is 4.6 MB. the total size downloaded for the two versions was 5538 MB. It means that

2.9x + 4.6y = 5538- - - - - - - - - - - -1

Substituting y = 4x into equation 1, it becomes

2.9x + 4.6 × 4x = 5538

2.9x + 18.4x = 5538

21.3x = 5538

x = 5538/21.3

x = 260

6 0

3 years ago

Pls i need help in this

timurjin [86]

It’s a blank screen .. what’s the question ?

7 0

2 years ago

Which expression is equivalent to 18c-6d? A: 2(9c-6d)

MakcuM [25]

Answer: answer is C because if you do 2x9 abd 2x3 you 18c-6d and you cant subtract thise cause they have different variables

Step-by-step explanation:

7 0

3 years ago

Read 2 more answers

X+1.793=2.42

Varvara68 [4.7K]

The right answer is
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4 0

2 years ago

An appliance manufacturer claims to have developed a compact microwave oven that consumes a mean of no more than 250 W. From pre

melamori03 [73]

Answer:

We conclude that a compact microwave oven consumes a mean of more than 250 W.

Step-by-step explanation:

We are given that an appliance manufacturer claims to have developed a compact microwave oven that consumes a mean of no more than 250 W with a population standard deviation of 15 W.

They take a sample of 20 microwave ovens and find that they consume a mean of 257.3 W.

Let $\mu$ = mean power consumption for microwave ovens.

So, Null Hypothesis, $H_0$ : $\mu$ $\leq$ 250 W {means that a compact microwave oven consumes a mean of no more than 250 W}

Alternate Hypothesis, $H_A$ : $\mu$ > 250 W {means that a compact microwave oven consumes a mean of more than 250 W}

The test statistics that would be used here One-sample z test statistics as we know about the population standard deviation;

T.S. = $\frac{\bar X-\mu}{\frac{\sigma}{\sqrt{n} } }$ ~ N(0,1)

where, $\bar X$ = sample mean power consumption for ovens = 257.3 W

σ = population standard deviation = 15 W

n = sample of microwave ovens = 20

So, the test statistics = $\frac{257.3-250}{\frac{15}{\sqrt{20} } }$

= 2.176

The value of z test statistics is 2.176.

Now, at 0.05 significance level the z table gives critical value of 1.645 for right-tailed test.

Since our test statistic is more than the critical value of t as 2.176 > 1.645, so we have sufficient evidence to reject our null hypothesis as it will fall in the rejection region due to which we reject our null hypothesis.

Therefore, we conclude that a compact microwave oven consumes a mean of more than 250 W.

7 0

2 years ago