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3 years ago

Can someone explain to me how to do this ? please

Mathematics

1 answer:

Maru [420]3 years ago

8 0

Step-by-step explanation:

Ex. 4 (2n- 5) = 3n + 10

So since there is a number outside the parenthesis (which is in the first term) You have to distribute the number by multiply 4 to 2n and to -5.

(4*2n) (4*-5) = 6n - 20 (ALWAYS Carry the negative sign when you have a negative answer.)

Then, Do the addition/subtraction property which would be:

6n - 20 = 3n + 10

-3n +20 -3n + 20

3n = 30

/3 /3

n = 10

Hopefully this helps.

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Negative three eighth minus one tenth A. 19/40 B. -19/40 c.-3/8 D. 2/9

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B. -19/40 is the answer.

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4 years ago

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What's the ratio of 75 to 80?

oksano4ka [1.4K]

Answer:

75:80 OR 15:16

Step-by-step explanation:

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3 years ago

There are 7 acts in a talent show.

lara31 [8.8K]

Answer:

Event A: 1/35

Event B: 1/840

Explanation:

Event A

For the event A, the order of the first 4 acts does not matter.

The number of different four acts taken from a set of seven acts, when the order does not matter, is calculated using the concept of combinations.

Thus, the number of ways that the first four acts can be scheduled is:

$C(m,n)=\dfrac{m!}{n!(m-n)!}$

$C(7,4)=\dfrac{7!}{4!(7-4)!}=\dfrac{7!}{4!(3)!}=35$

And the number of ways that four acts is the singer, the juggler, the guitarist, and the violinist, in any order, is 1: C(4,4).

Therefore the probability of Event A is:

$P(A)=1/35$

Event B

Now the order matters. The difference between combinations and permutations is ordering. When the order matters you need to use permutations.

The number of ways in which four acts can be scheculed when the order matters is:

$P(m,n)=\dfrac{m!}{(m-n)!}$

$P(m,n)=\dfrac{7!}{(7-4)!}=P(m,n)=\dfrac{7!}{4!}=840$

The number of ways the comedian is first, the guitarist is second, the dancer is third, and the juggler is fourth is 1: P(4,4)

Therefore, the probability of Event B is:

$P(B)=1/840$

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4 years ago

Provide an appropriate response. In order to efficiently bid on a contract, a contractor wants to be 95% confident that his erro

lidiya [134]

Answer:

d. 20

Step-by-step explanation:

Standard deviation is 4.5

Margin error for the problem is 2 hours

Probability 95%, that means that the siginficance level α is 1 – p

α = 1 – 0.95 = 0.05

margin of error (ME) can be defined as follows

ME = Z(α/2) * standard deviation/ √n

Where n is the sample size

Z(0.05/2) = Z(0.025)

Using a z table Z = 1.96

Now, replacing in the equation and find n

2 = 1.96 * 4.5/ √n

2 = 8.82/√n

√n = 8.82/2

√n = 4.41

n = 4.41^2

n = 19.44 ≈ 20

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3 years ago

How much fabric is needed to create the lateral faces of the tent?

jek_recluse [69]

Left and right side: 6.4*7=44.8
44.8+44.8=89.6
front (where the zipper is) and back: half of 5*8=20
20+20=40

40+89.6=129.6

the area of the bottom is 7*8=56

the total area is 129.6+56=185.6

I am not sure what lateral area includes. To me, the answer should be 129.6, but 129.6 is not a choice.
I'd suggest 185.6, the total surface area.

7 0

3 years ago

Can someone explain to me how to do this ? please ​

Can someone explain to me how to do this ? please