Expand and simplify the following expression:
(2x + 1)^2 – (2x + 1)

Answer:

6

Step-by-step explanation:

.....................

Answer:

6

Step-by-step explanation:

pecentage calculator.what is 75 percent of 8?=6

Answer:

3.5 °C

Step-by-step explanation:

        3 x 7 = 21

        21 + 8 =29

       29 ÷ 8 = 3.5

       3.5 °C

Answer:

3.5⁰ C is the mean temperature for the first 8 days in January.

Answer:

1

Step-by-step explanation:

When you multiply two quantities under a root, it is just like normal multiplication. 2*18 is 36, which is the perfect square of six. Since this number can be expressed as p/q (where p and q are integers; the values here are 6 and 1), it is rational.

Answer:

0.8612 = 86.12% probability that the sample proportion will differ from the population proportion by less than 3%

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 normal distributions can be solved using the z-score formula.

In a set with mean [tex]\mu[/tex] and standard deviation [tex]\sigma[/tex], the z-score of a measure X is given by:

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

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 p-value, we get the probability that the value of the measure is greater than X.

Central Limit Theorem

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

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

For a proportion p in a sample of size n, the sampling distribution of the sample proportion will be approximately normal with mean [tex]\mu = p[/tex] and standard deviation [tex]s = \sqrt{\frac{p(1-p)}{n}}[/tex]

Suppose a large consignment of televisions contained 11% defectives.

This means that [tex]p = 0.11[/tex]

Sample of size 237

This means that [tex]n = 237[/tex]

Mean and standard deviation:

[tex]\mu = p = 0.11[/tex]

[tex]s = \sqrt{\frac{p(1-p)}{n}} = \sqrt{\frac{0.11*0.89}{237}} = 0.0203[/tex]

What is the probability that the sample proportion will differ from the population proportion by less than 3%?

P-value of Z when X = 0.11 + 0.03 = 0.14 subtracted by the p-value of Z when X = 0.11 - 0.03 = 0.08. So

X = 0.14

[tex]Z = \frac{X - \mu}{\sigma}[/tex]

By the Central Limit Theorem

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.14 - 0.11}{0.0203}[/tex]

[tex]Z = 1.48[/tex]

[tex]Z = 1.48[/tex] has a p-value of 0.9306

X = 0.08

[tex]Z = \frac{X - \mu}{s}[/tex]

[tex]Z = \frac{0.08 - 0.11}{0.0203}[/tex]

[tex]Z = -1.48[/tex]

[tex]Z = -1.48[/tex] has a p-value of 0.0694

0.9306 - 0.0694 = 0.8612

0.8612 = 86.12% probability that the sample proportion will differ from the population proportion by less than 3%

Answer:

He should have subtracted 2 from each side to find the solution for x+2 =0

Step-by-step explanation:

(x + 2)(x - 7) = 0

Using the zero product property

x+2 = 0   x-7=0

x+2-2=0-2    x-7+7=0+7

x = -2            x=7

He should have subtracted 2 from each side to find the solution for x+2 =0

Step-by-step explanation:

the steps he took are correct but the answer of x is somehow wrong because

(x+2)=0

x = -2

and not x = 2

Answer:

6: 15

Step-by-step explanation:

When finding the ratio of anything, you must count each side.

Answer:

4.7 to nearest tenth.

Step-by-step explanation:

By Pythagoras:

8^2 = x^2 + 6.5^2

x^2 = 8^2 - 6.5^2

x^2 = 64 - 42.25 = 21.75

x = √21.75

= 4.6637

9514 1404 393

Answer:

  A. (1, - 3/2)

Step-by-step explanation:

The coordinate of the midpoint is the average of the endpoint coordinates.

  M = (A +B)/2

  M = ((1, 2) +(1, -5))/2 = (1+1, 2-5)/2 = (2, -3)/2

  M = (1, -3/2) . . . . . matches choice A

Answer:

A. (1, - 3/2)

Step-by-step explanation:

Answer:

Step-by-step explanation:

either do 23 x23

or

23 x 16 ( do this first )

Answers:

=================================================

Explanation:

Any conditional statement is of the form "If P, then Q"

P is the hypothesis, which is the initial set up to lead to the conclusion Q

As an example, the sentence "If it rains, then it gets wet on the road" has P = "it rains" as the hypothesis and Q = "it gets wet on the road" as the conclusion.

-------------

In short, the format is "If hypothesis, then conclusion".

The scale is 5/4

Because:

Let's take

20/16 = 5/4

20/16 = 5/4

15/12 = 5/4

Answer:

5/2 or 5:2 ratio is the reduced fraction from the scale factor A to B.

Answer:

Let p = the speed of the plane

and w = the speed of the wind

It takes the plane 3 hours to go 600 miles when against the headwind and 2 hours to go 600 miles with the headwind. So we set up a system of equations.

600mi3hr=p−w600mi2hr=p+w

Solving for the left sides we get:

200mph = p - w

300mph = p + w

Now solve for one variable in either equation. I'll solve for x in the first equation:

200mph = p - w

Add w to both sides:

p = 200mph + w

Now we can substitute the x that we found in the first equation into the second equation so we can solve for w:

300mph = (200mph + w) + w

Combine like terms:

300mph = 200mph + 2w

Subtract 200mph on both sides:

100mph = 2w

Divide by 2:

50mph = w

So the speed of the wind is 50mph.

Now plug the value we just found back in to either equation to find the speed of the plane, I'll plug it into the first equation:

200mph = p - 50mph

Add 50mph on both sides:

250mph = p

So the speed of the plane in still air is 250mph.

Answer:

140miles/hour

Step-by-step explanation:

Speed of airplane + speed of wind

=240miles/3 hours + 240miles/4 hours

=80miles/hour +60miles/hour

= 140miles/hour

Answer:

2 hours and 30 minutes

Step-by-step explanation:

25/5 = 5 Divide to find out how many fives are there in 25.

5 x 30 = 150 minutes (multiply 5 by 30 to find out how many minutes)

150/60 = 2.5 hours or in other words, 2 hours and 30 minutes ( Convert the minutes into hours by dividing by 60)

Answer:

126 cubic cm

Step-by-step explanation:

6 x 7 x 2 = 84

2 x 3 x 7 = 42

84 + 42 = 126

(i separated the shape to two rectangular prisms)

SOLUTION

• -4 = 5(p -2)

 -4 = (5)(p) + (5)(-2)   • Distribute

 -4 = 5p + (-10)

 -4 = 5p - 10

• 5p - 10 = -4

• 5p - 10 + 10 = -4 + 10

  5p = 6

• [tex]\frac{5p}{5} = \frac{6}{5}[/tex]

  p = [tex]\frac{6}{5}[/tex]

Answer:

OMGGGG wanna work on this together I need this question too

Answer:

5 divided by 1/5

5 x 5/1 = 25, he has 25 servings.

Answer:

2.99*10⁷ m/s

Step-by-step explanation:

29900000 meters per second written in scientific notation is 2.99*10⁷ m/s

Answer:

i dont know hun i am very sorry

Step-by-step explanation:

I'm assuming all the numbers here mistakenly got copied twice.

Let A(t) denote the amount (in kg) of salt in the tank at time t. The solution starts with 70 kg of salt, so (a) A(0) = 70.

I also assume there is more to the question, so I'll just go ahead and build the differential equation to model this situation, and solve it.

Pure water is flowing into the tank, so no salt is being introduced. The concentration of salt at time t is A(t)/2000 kg/L, and solution is drained from the tank at a rate of 4 L/min, which means salt is being removed at a rate of

(4 L/min) (A(t)/2000 kg/L) = A(t)/500 kg/min = 0.002 A(t) kg/min

Thus the amount of salt (ignoring units now) in the tank changes according to the DE,

dA(t)/dt = -0.002 A(t)

which is easy to solve because it's linear with constant coefficients.

Without going into too much detail:

dA(t)/dt + 0.002 A(t) = 0

exp(0.002t ) dA(t)/dt + 0.002 exp(0.002t ) A(t) = 0

d/dt [exp(0.002t ) A(t)] = 0

exp(0.002t ) A(t) = C

A(t) = C exp(-0.002t )

Given A(0) = 70, solve for C :

70 = C exp(0) = C

Hence

A(t) = 70 exp(-0.002t )

Answer:

Step-by-step explanation:

[tex]sin({\alpha\over{2}})=\pm\sqrt{{1-cos(\alpha)\over{2}}}\Rightarrow sin({30\over{2}})=+\sqrt{{1-{\sqrt{3}\over{2}}\over{2}}}={\sqrt{{2-\sqrt{3}}}\over{2}}[/tex]

[tex]cos({\alpha\over{2}})=\pm\sqrt{{1+cos(\alpha)}\over{2}}=+\sqrt{{1+{\sqrt{3}\over{2}}\over{2}}}={\sqrt{{2+\sqrt{3}}}\over{2}}[/tex]

substituting we get:

[tex]tg(15)=\sqrt{{2-\sqrt{3}}\over{2+\sqrt{3}}}[/tex]

Answer: x=3

Step-by-step explanation:

from figure

=>tan45= x/3

=>x= 3tan45

=>x=3

Answer:

Step-by-step explanation:

here hypotenuse is x

since it is an isosceles triangle the other side of the triangle also must 3.

using pythagoras theorem

a^2 + b^2 = c^2

3^2 + 3^2 = x^2

9 + 9 = x^2

18 = x^2

[tex]\sqrt{18} = x[/tex]

Answer:

Sn=−6650

Step-by-step explanation:

Answer:

b/2 + 8 = 86

b = 156

Step-by-step explanation:

Half the comics is b/2

b/2 + 8 = 86

Subtract 8 from both sides

b/2 = 78

multiply both sides by 2

b = 156

Answer:

hope this helps

Step-by-step explanation:

the answer is 3n+4

Answer:

..........

Step-by-step explanation:

[tex]\pi[/tex]