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2 years ago

Solve this root2x-7 =7

Mathematics

2 answers:

torisob [31]2 years ago

7 0

Answer:

28.

Step-by-step explanation:

1) the range of x is: 2x-7>0; ⇔ x>3.5.

2) the solution is:

$\sqrt{2x-7}=7;$

2x-7=49;

2x=56; ⇔ x=28 (28>3.5, belongs to the range of x above).

Karo-lina-s [1.5K]2 years ago

5 0

-14??
Idek tbh it’s kinda hard

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The rectangle shown is dilated by a scale factor of 3.

Law Incorporation [45]

Given that the image was dilated by scale factor 3 then:
a] Length of the dilated side will be:
length/width=(original length/width)*(scale factor)
length=3*10=30 in
Width=3*6=18 in
thus the dimensions of the new image will be:
30 in by 18 in

b. The diagram below represent s the rectangle. 1 cm represent 10 inches

7 0

3 years ago

In a random sample of 18 families, the average weekly food expense was $95.60 with a sample standard deviation of $22.50. Determ

shepuryov [24]

Answer:

t-distribution should be used to construct a confidence interval.

Step-by-step explanation:

We are given that a random sample of 18 families, the average weekly food expense was $95.60 with a sample standard deviation of $22.50.

We have to determine whether a normal distribution (Z values) or a t- distribution should be used or whether neither of these can be used to construct a confidence interval.

Since in this question we are provided with;

Sample average weekly food expense, $\bar X$ = $95.60

Sample standard deviation, s = $22.50

Sample of families, n = 18

The distribution that we will use here to construct a confidence interval will be t-distribution because in the question we don't know anything about population standard deviation $(\sigma)$ .

Normal distribution is used when we know population standard deviation $(\sigma)$ .

So, the pivotal quantity for confidence interval that will be used is One-sample t-test statistics;

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

Therefore, t-distribution should be used to construct a confidence interval.

3 0

3 years ago

Hey! i’ll give brainliest please help

Iteru [2.4K]

Answer:

A subject and a predicate

Step-by-step explanation:

Have a good day :)

7 0

3 years ago

A triangle has sides 12cm, 9cm and 15cm. Is the triangle right-angled? Justify your answer

marusya05 [52]

Answer:

yes

Step-by-step explanation:

Yes this triangle is right angled and can be justified using the Pythagorean theorem. The theorem states that: $a^{2} +b^{2} = c^{2}$ . Substitute using the given values:

(9^2)+(12^2)=15^2

81 + 144 = 255

255 = 255.

It satisfies the theorem therefore it is a right angle triangle.

3 0

3 years ago

Suppose that a class contains 15 boys and 30 girls, and that 10 students are to be selected at random for a special assignment.

natka813 [3]

Prob of selected students times prob of selecting boys times prob of selecting 3 boys
total students = 15b + 30g = 45 students

1. 10s/45t = 0.22
2. 15b/45t = 0.33
3. 3b/15b = 0.2

0.22×0.33×0.2=0.0148

1.48%

I'm not sure 100%... double check answer please

3 0

3 years ago