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3 years ago

Which statement is true about the difference 2√7-√28

1 answer:

7 0

It seems like there are answer choices but you forgot to post them. If you want to simplify then

2*sqrt(7) - sqrt(28) = 2*sqrt(7) - sqrt(4*7)
2*sqrt(7) - sqrt(28) = 2*sqrt(7) - sqrt(4)*sqrt(7)
2*sqrt(7) - sqrt(28) = 2*sqrt(7) - 2*sqrt(7)
2*sqrt(7) - sqrt(28) = (2-2)*sqrt(7)
2*sqrt(7) - sqrt(28) = (0)*sqrt(7)
2*sqrt(7) - sqrt(28) = 0

So the whole complicated expression simplifies to 0 (zero)

This is because sqrt(28) = 2*sqrt(7) when you simplify sqrt(28)

Side Note: "sqrt" is shorthand for "square root"

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Rashad draws a figure and divides it into equal parts. Two of the parta are red. The other 4 parts are blue. Rashad saya that 2/

Juliette [100K]

Let
x--------------> the complete figure
we know that
the figure is divided into 6 equal parts
x= (x/6)+(x/6)+(x/6)+(x/6)+(x/6)+(x/6)
red=(x/6)+(x/6)--------> red=(2x/6)=x/3
blue=(x/6)+(x/6)+(x/6)+(x/6)=(4x/6)=2x/3

Rashad say that 2/4 of the figure is red-------> Rashad is wrong
because (2/4) It is half of the figure

the correct thing is to say (1/3) o the figure is red and (2/3) of the figure is blue

3 0

3 years ago

Lengths of newborn girls are normally distributed with a mean of 49.2 cm and a standard deviation of 1.8 centimeters. Consider a

Elza [17]

The answer is 1683.

Hope this helps.

3 0

3 years ago

For f(x) = 0.02(2)^x find the average rate of change from x= 3 to x= 8

Fudgin [204]

None of the offered choices is correct.

f(3) = 0.02·2³ = 0.02·8 = 0.16

f(8) = 0.02·2⁸ = 0.02·256 = 5.12

Then the average rate of change is

... (f(8) - f(3))/(8 - 3) = (5.12 -0.16)/5 = 4.96/5 = 0.992

5 0

3 years ago

A grocer mixed walnuts worth $1.02 per pound with peanuts worth $0.99 per pound. If she made 69 pounds of a mixture worth $1 per

Nataly [62]

The cost of the mixture is $69 *$1 = $69. If all 69 pounds were peanuts, the cost would be 69*$0.99 = $68.31, which is $0.69 less. Each pound of walnuts used instead of peanuts adds $0.03 to the cost of the mixture, so there were $0.69/$0.03 = 23 pounds of walnuts.
_____ 
Let w represent the number of pounds of walnuts in the mixture. Then 69-w is the number of pounds of peanuts. The cost of the mixture will be 
1.02w + 0.99(69-w) = 1.00*69 dollars 
0.03w + 68.31 = 69.00 
w = (69.00 - 68.31)/0.03 = 0.69/0.03 = 23

6 0

3 years ago

A company that produces fine crystal knows from experience that 13% of its goblets have cosmetic flaws and must be classified as

Kisachek [45]

Answer:

(a) The probability that only one goblet is a second among six randomly selected goblets is 0.3888.

(b) The probability that at least two goblet is a second among six randomly selected goblets is 0.1776.

Step-by-step explanation:

Let X = number of seconds in the batch.

The probability of the random variable X is, p = 0.31.

The random variable X follows a Binomial distribution with parameters n and p.

The probability mass function of X is:

$P(X=x)={n\choose x}p^{x}(1-p)^{n-x};\ x=0,1,2,3...$

(a)

Compute the probability that only one goblet is a second among six randomly selected goblets as follows:

$P(X=1)={6\choose 1}0.13^{1}(1-0.13)^{6-1}\\=6\times 0.13\times 0.4984\\=0.3888$

Thus, the probability that only one goblet is a second among six randomly selected goblets is 0.3888.

(b)

Compute the probability that at least two goblet is a second among six randomly selected goblets as follows:

P (X ≥ 2) = 1 - P (X < 2)

$=1-{6\choose 0}0.13^{0}(1-0.13)^{6-0}-{6\choose 1}0.13^{1}(1-0.13)^{6-1}\\=1-0.4336+0.3888\\=0.1776$

Thus, the probability that at least two goblet is a second among six randomly selected goblets is 0.1776.

(c)

If goblets are examined one by one then to find four that are not seconds we need to select either 4 goblets that are not seconds or 5 goblets including only 1 second.

P (4 not seconds) = P (X = 0; n = 4) + P (X = 1; n = 5)

$={4\choose 0}0.13^{0}(1-0.13)^{4-0}+{5\choose 1}0.13^{1}(1-0.13)^{5-1}\\=0.5729+0.3724\\=0.9453$

Thus, the probability that at most five must be selected to find four that are not seconds is 0.9453.

8 0

3 years ago