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3 years ago

SIMPLE Factoring by Grouping

1 answer:

7 0

Group together the terms that have "like" variables or constants in them. The first 2 terms both have an x, but the second 2 don't, so the first two are grouped together. The second 2 terms, while they do not have a common variable, both have the number 2. So those are grouped together.
(xa - xb) - (2a + 2b)--> x(a-b) - 2(a-b). Now you can actually factor out the like term (a-b) to get this: (a-b)(x-2).

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Please Help I need help and fast

IrinaVladis [17]

Answer:

150 m/s

Step-by-step explanation:

3 0

3 years ago

What is x equal to? 3(x + 5) = 2(3x + 18)

Anna [14]

3(x + 5) = 2(3x + 18)
Use the distributive property:
3(x)+5(3)=2(3x)+18(2)
Simplify:
3x+15=6x+36
6x+36=3x+15
3x+36=15
3x=-21
x=-7

Check answer:
3(-7+5)=2(-21+18)
3(-2)=2(-3)
-6=-6

Hope this helps :)

7 0

3 years ago

Read 2 more answers

The Information Technology Department at a large university wishes to estimate the proportion of students living in the dormitor

nadya68 [22]

Answer:

$n=\frac{0.5(1-0.5)}{(\frac{0.05}{1.96})^2}=384.16$

And rounded up we have that n=385

Step-by-step explanation:

Previous concepts

A confidence interval is "a range of values that’s likely to include a population value with a certain degree of confidence. It is often expressed a % whereby a population means lies between an upper and lower interval".

The margin of error is the range of values below and above the sample statistic in a confidence interval.

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".

Solution to the problem

In order to find the critical value we need to take in count that we are finding the interval for a proportion, so on this case we need to use the z distribution. Since our interval is at 99% of confidence, our significance level would be given by $\alpha=1-0.99=0.01$ and $\alpha/2 =0.005$ . And the critical value would be given by:

$z_{\alpha/2}=-2.58, z_{1-\alpha/2}=2.58$

The margin of error for the proportion interval is given by this formula:

$ME=z_{\alpha/2}\sqrt{\frac{\hat p (1-\hat p)}{n}}$ (a)

And on this case we have that $ME =\pm 0.05$ and we are interested in order to find the value of n, if we solve n from equation (a) we got:

$n=\frac{\hat p (1-\hat p)}{(\frac{ME}{z})^2}$ (b)

We can use as an estimator for p $\hat p =0.5$ . And replacing into equation (b) the values from part a we got:

$n=\frac{0.5(1-0.5)}{(\frac{0.05}{1.96})^2}=384.16$

And rounded up we have that n=385

3 0

3 years ago

Use the commutative law of addition to write a equivalent expression ab+c

Scilla [17]

Answer:

c + ab

Step-by-step explanation:

The way an expression is written is the given you have presented to us.

The commutative law of addition would turn it around as

c + ab.

It just means change the order when adding. Not all systems allow this. It matters which way you put it in some systems.

5 0

3 years ago

Find the arc measure of AB. The measure of arc AB = ______ degrees

mariarad [96]

The picture is difficult to read, but it looks like
∠ADB = 2x²
∠ACB = 10x
These two angles have equal measure, so you have
2x² = 10x
2x(x -5) = 0 . . . . . subtract 10x and factor
x = 0, or x = 5

The measure of arc AB is twice the measure of either inscribed angle, so would be
arc AB = 2×10x
= 2×10×5
= 100 . . . . . degrees

Arc AB is 100°.

7 0

3 years ago