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3 years ago

Why 2+2=4 and not 2+2=22 ?

Mathematics

1 answer:

Lunna [17]3 years ago

8 0

2 + 2 = 4 because 4 is a sum of 1-digit numbers

2 + 2 ≠ 22 because 22 is the sum of 1-digit and 2-digit numbers

Step-by-step explanation:

Lets explain some important notes:

The 1-digit number consists of one digit, 4 is a one-digit number
The 2-digit number consists of two digits, ones digit and tens digit, 23 is a 2-digit number, the ones digit is 3 and the tens digit is 2, so its value is 20 + 3
The 3-digit number consists of ones digit, tens digit and the hundreds digit, 123 is a 3-digit number, the ones digit is 3, the tens digit is 2 and the hundreds digit is 1, so its value is 100 + 20 + 3

∵ 2 + 2 is the addition problem of two 1-digit numbers

∴ There sum will be 4 which is also 1-digit number

∴ 2 + 2 must be 4

∵ 22 is a two digit number

∴ Its value is 20 + 2 ⇒ not 2 + 2

∴ 2 + 2 can not be 22

2 + 2 = 4 because 4 is a sum of 1-digit numbers

2 + 2 ≠ 22 because 22 is the sum of 1-digit and 2-digit numbers

Learn more:

You can learn more about the place value of numbers in brainly.com/question/13174282

#LearnwithBrainly

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A semi circle is drawn on each side of the square as shown the square has sides length of 2 pi what is the area of the resulting

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Step-by-step explanation:

First you find out the area of the square.

Then you find the area of the circle.

After this you add the Two area together.

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3 years ago

Find the value of xx, yy, and zz in the parallelogram below.

Scrat [10]

Answer: x = 92, y = -119

Step-by-step explanation:

Opposite sides of a parallelogram are equal.

x + 6 = 98

x = 92

127 = -y + 8

-y = 119

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2 years ago

Read 2 more answers

Given: F(x) = 5x - 6 and G(x) = x - 4

fomenos

Answer:

Correct choice is $\dfrac{x+26}{5}$

Step-by-step explanation:

1. If $F(x)=5x-6,$ then you can find the inverse $F^{-1}(x):$

$y=5x-6,\\ \\5x=y+6,\\ \\x=\dfrac{y+6}{5},\\ \\F^{-1}(x)=\dfrac{x+6}{5}.$

2. If $G(x)=x-4,$ then

$y=x-4,\\ \\x=y+4,\\ \\G^{-1}(x)=x+4.$

3. Hence,

$G^{-1}(F^{-1}(x))=G^{-1}\left(\dfrac{x+6}{5}\right)=\dfrac{x+6}{5}+4=\dfrac{x+26}{5}.$

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3 years ago

Consider testing H^0: u=20 against H^a: u<20 where u is the mean number of latex gloves used per week by all hospital employe

iragen [17]

Answer:

Part a: P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=46-1=45$

Since is a one sided test the p value would be:

$p_v =P(t_{(45)}$

Part b: Conclusion

If we compare the p value and the significance level given $\alpha=0.01$ we see that $p_v>\alpha$ so we can conclude that we have enough evidence to fail reject the null hypothesis, and we can conclude that the true mean is not lower than 20 at 1% of signficance.

a. There is insufficient evidence to reject h^0

Step-by-step explanation:

Data given and notation

$\bar X=19.1$ represent the sample mean

$s=11.8$ represent the sample standard deviation

$n=46$ sample size

$\mu_o =20$ represent the value that we want to test

$\alpha=0.01$ represent the significance level for the hypothesis test.

t would represent the statistic (variable of interest)

$p_v$ represent the p value for the test (variable of interest)

State the null and alternative hypotheses.

We need to conduct a hypothesis in order to check if the mean is lower than 20, the system of hypothesis would be:

Null hypothesis: $\mu \geq 20$

Alternative hypothesis: $\mu < 20$

If we analyze the size for the sample is > 30 but we don't know the population deviation so is better apply a t test to compare the actual mean to the reference value, and the statistic is given by:

$t=\frac{\bar X-\mu_o}{\frac{s}{\sqrt{n}}}$ (1)

t-test: "Is used to compare group means. Is one of the most common tests and is used to determine if the mean is (higher, less or not equal) to an specified value".

Calculate the statistic

We can replace in formula (1) the info given like this:

$t=\frac{19.1-20}{\frac{11.8}{\sqrt{46}}}=-0.517$

Part a: P-value

The first step is calculate the degrees of freedom, on this case:

$df=n-1=46-1=45$

Since is a one sided test the p value would be:

$p_v =P(t_{(45)}$

Part b: Conclusion

a. There is insufficient evidence to reject h^0

5 0

2 years ago

20 POINTS N BRAINLIEST!!16.Alun has a part-time job working as a bus boy at a

olchik [2.2K]

Answer:

a)E=.05t +34

b)$54

c)$600

Step-by-step explanation:

a) he gets 5% of tips out of all tips people gave to the restaurant , 5% --> .05 (as a decimal) --> this is "t"

he earns an extra $34 a night of work. --> this is the constant

E= --> the total earned that night

E=.05t +34

b) simply plug in the total tip into the equation

E=.05(400) + 34

E=$54

--> he earned $54 that night

c) since we are given the total earned that night, we now plug in for y. in this case we plug "$64" for y

we find t, which is tip the restaurant was given

--> 64 = .05t +34

-34. -34

30= .05t ---> divide by .05 each side

t= $600

the restaurant was tiped 600 dollars and Alun was paid 64 dollars that night of work

hoped this helped:)

3 0

3 years ago