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3 years ago

11

Emily’s mother is 4 times as old as Emily now in 6 years Emily’s mother will be 3 times as old as Emily will be then how old is

Emily now?

2 answers:

mote1985 [20]3 years ago

7 0

Answer:

mother=m

e=emily

m=4e

m+6=3(e+6)

substitute the first equation into the second.

4e+6=3(e+6)

4e+6=3e+18

4e=3e+12

e=12

Emily is currently 12 years old.

frosja888 [35]3 years ago

7 0

Answer:

12 years old.

Step-by-step explanation:

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What is the mixed number form<br> of 33/8

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HCF of 8 that will go as much as possible to 33

4*8=32 and denominator is 8

33-32=1 which is the numerator

Answer is :

4 1/8

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Find two consecutive odd integers whose sum is 36.

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2 consecutive odd integers...x and x + 2

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Scores of an IQ test have a bell-shaped distribution with a mean of 100 and a standard deviation of 12. Use the empirical rule t

MissTica

Answer:

A) 99.7% of people have an IQ between 64 and 136.

B) 5% of people have an IQ score less than 76 or greater than 124.

C) 16% of people have an IQ score greater than 112.

Step-by-step explanation:

The Empirical Rule tells us that, in a normal or 'bell-shaped' distribution, 68% of the data is one standard deviation from the mean, 95% of the data is two standard deviations from the mean, and 99.7% of the data is three standard deviations from the mean.

A) 64 and 136 are 3 standard deviations away from the mean, so 99.7% of people have an IQ between 64 and 136.

B) 76 and 124 are 2 standard devations away from the mean, but the answer is asking what percentage is not between them. 100% - 95% gives us 5%.

C) 112 is one standard deviation away from the mean. If we want to find the percentage greater, then we can do 100% - 50% (as 112 is to the left of the mean), then we can take half of 68 to get 34%, and after subtracting 50% and 34% from the 100%, we get 16%.

8 0

3 years ago

Find the angle between the given vectors. Round your answer, in degrees, to two decimal places. u=⟨2,−6⟩u=⟨2,−6⟩, v=⟨4,−7⟩

NISA [10]

Answer:

$\theta = 108.29$

Step-by-step explanation:

Given

$u =$

$v =$

Required:

Calculate the angle between u and v

The angle $\theta$ is calculated as thus:

$cos\theta = \frac{u.v}{|u|.|v|}$

For a vector

$A =$

$A = a * b$

$cos\theta = \frac{u.v}{|u|.|v|}$ becomes

$cos\theta = \frac{.}{|u|.|v|}$

$cos\theta = \frac{2*6+4*-7}{|u|.|v|}$

$cos\theta = \frac{12-28}{|u|.|v|}$

$cos\theta = \frac{-16}{|u|.|v|}$

For a vector

$A =$

$|A| = \sqrt{a^2 + b^2}$

So;

$|u| = \sqrt{2^2 + 6^2}$

$|u| = \sqrt{4 + 36}$

$|u| = \sqrt{40}$

$|v| = \sqrt{4^2+(-7)^2}$

$|v| = \sqrt{16+49}$

$|v| = \sqrt{65}$

So:

$cos\theta = \frac{-16}{|u|.|v|}$

$cos\theta = \frac{-16}{\sqrt{40}*\sqrt{65}}$

$cos\theta = \frac{-16}{\sqrt{2600}}$

$cos\theta = \frac{-16}{\sqrt{100*26}}$

$cos\theta = \frac{-16}{10\sqrt{26}}$

$cos\theta = \frac{-8}{5\sqrt{26}}$

Take arccos of both sides

$\theta = cos^{-1}(\frac{-8}{5\sqrt{26}})$

$\theta = cos^{-1}(\frac{-8}{5 * 5.0990})$

$\theta = cos^{-1}(\frac{-8}{25.495})$

$\theta = cos^{-1}(-0.31378701706)$

$\theta = 108.288386087$

<em></em> $\theta = 108.29$ <em> (approximated)</em>

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2 years ago

The sets of numbers 3, 4, 5 and 8, 15, 17 are Pythagorean triples. Use what you know about the Pythagorean Theorem and explain o

konstantin123 [22]

Answer:

When we have 3 numbers, like:

a, b and c.

Such that:

a < b < c.

These numbers are a Pythagorean triplet if the sum of the squares of the two smaller numbers, is equal to the square of the larger number:

a^2 + b^2 = c^2

This is equivalent to the Pythagorean Theorem, where the sum of the squares of the cathetus is equal to the hypotenuse squared.

Now that we know this, we can check if the given sets are Pythagorean triples.

1) 3, 4, 5

Here we must have that:

3^2 + 4^2 = 5^2

solving the left side we get:

3^2 + 4^2 = 9 + 16 = 25

and the right side:

5^2 = 25

Then we have the same in both sides, this means that these are Pythagorean triples.

2) 8, 15, 17

We must have that:

8^2 + 15^2 = 17^2

Solving the left side we have:

8^2 + 15^2 = 64 + 225 = 289

And in the right side we have:

17^2 = 17*17 = 289

So again, we have the same result in both sides, which means that these numbers are Pythagorean triples

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2 years ago