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2 years ago

Explain how you can tell if the expressions 7x – 4 and 6x – 4 – x are equivalent.

Mathematics

1 answer:

Alina [70]2 years ago

8 0

Hey there!

Combine Like Terms and see if the expressions are equivalent or not.

6x-4-x

6x-x-4

5x-4

Is 5x-4 equivalent to 7x-4? No.

Hope everything is clear.

Let me know if you have any questions!

Always remember: Knowledge is power!

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Help!! BRAINLIEST TOO!

natulia [17]

Answer:

36.5 inches

Step-by-step explanation:

Given

See attachment for the given data

Required

Which length is closest to 4.2lb

The given data is a linear dataset.

So, we start by calculating the slope (m)

$m =\frac{y_2 - y_1}{x_2 - x_1}$

Pick any two corresponding points from the table

So, we have:

$(x_1,y_1) = (8,1.21)$

$(x_2,y_2) = (12,1.63)$

So:

$m =\frac{y_2 - y_1}{x_2 - x_1}$

$m =\frac{1.63 - 1.21}{12 - 8}$

$m =\frac{0.42}{4}$

$m =0.105$

The linear equation is then calculated using:

$y = m(x - x_1) + y_1$

This gives:

$y = 0.105 * (x - 8) + 1.21$

Open bracket

$y = 0.105x - 0.84 + 1.21$

$y = 0.105x + 0.37$

To get the length closest to 4.2lb,

we set $y = 4.2$

Then solve for x

So, we have:

$y = 0.105x + 0.37$

$4.2 = 0.105x + 0.37$

Collect like terms

$0.105x= 4.2 - 0.37$

$0.105x= 3.83$

Solve for x

$x= 3.83/0.105$

$x\approx 36.5$

4 0

3 years ago

What is (f-g)(x)? f(x)=x^4-x^2+9 g(x)=x^3+3x^2+12

sweet-ann [11.9K]

X^4 - x^2 + 9 - (x^3 + 3x^2 + 12) =

x^4 - x^3 - 4x^2 - 3

6 0

3 years ago

The average Act score follows a normal distribution, with a mean of 21.1 and a standard deviation of 5.1. What is the probabilit

ohaa [14]

Answer:

0.43% probability that the mean IQ score of 50 randomly selected people will be more than 23

Step-by-step explanation:

To solve this question, we need to understand the normal probability distribution and the central limit theorem.

Normal probability distribution

Problems of normally distributed samples are solved using the z-score formula.

In a set with mean $\mu$ and standard deviation $\sigma$ , the zscore of a measure X is given by:

$Z = \frac{X - \mu}{\sigma}$

The Z-score measures how many standard deviations the measure is from the mean. After finding the Z-score, we look at the z-score table and find the p-value associated with this z-score. This p-value is the probability that the value of the measure is smaller than X, that is, the percentile of X. Subtracting 1 by the pvalue, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

The Central Limit Theorem estabilishes that, for a normally distributed random variable X, with mean $\mu$ and standard deviation $\sigma$ , the sampling distribution of the sample means with size n can be approximated to a normal distribution with mean $\mu$ and standard deviation $s = \frac{\sigma}{\sqrt{n}}$ .

For a skewed variable, the Central Limit Theorem can also be applied, as long as n is at least 30.

In this question:

$\mu = 21.1, \sigma = 5.1, n = 50, s = \frac{5.1}{\sqrt{50}} = 0.7212$

What is the probability that the mean IQ score of 50 randomly selected people will be more than 23

This is 1 subtracted by the pvalue of Z when X = 23. So

$Z = \frac{X - \mu}{\sigma}$

By the Central Limit Theorem

$Z = \frac{X - \mu}{s}$

$Z = \frac{23 - 21.1}{0.7212}$

$Z = 2.63$

$Z = 2.63$ has a pvalue of 0.9957

1 - 0.9957 = 0.0043

0.43% probability that the mean IQ score of 50 randomly selected people will be more than 23

5 0

3 years ago

PLEASE ANSWER AS FAST AS YOU CAN !Which of the following choices must be true in order for ΔABC ≅ ΔEDC by the AAS congruency the

Goryan [66]

Answer:

A = E and B = D

Step-by-step explanation:

AAS means triangles are congruent if two pairs of corresponding angles and a pair of opposite sides are equal in both triangles. In this, A corresponds to E and B to D. BC and CD are congruent. Therefore the triangles are congruent

6 0

3 years ago

A line m is perpendicular to an angle bisector of ∠A. The sides of ∠A intersect this line m at points M and N. Prove that △AMN i

Ray Of Light [21]

Answer:

Step-by-step explanation:

Given: A line m is perpendicular to the angle bisector of ∠A. We call this

intersecting point as D. Hence, in figure ∠ADM=∠ADN =90°.

AD is angle bisector of ∠A. Hence, ∠MAD=∠NAD.

To Prove: ΔAMN is an isosceles triangle. i.e any two sides in ΔAMN are

equal.

Solution: Now, In ΔADM and ΔADN

∠MAD=∠NAD ...(1) (∵Given)

AD=AD ...(2) (∵common side)

∠ADM=∠ADN ...(3) (∵Given)

Hence, from equation (1),(2),(3) ΔADM ≅ ΔADN

( ∵ ASA congruence rule)

⇒ AM=AN

Now, In Δ AMN

AM=AN (∵ Proved)

Hence, ΔAMN is an isosceles triangle.

7 0

3 years ago