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Serhud [2]
2 years ago
15

Help please I need an answer for this fast

Mathematics
1 answer:
castortr0y [4]2 years ago
6 0

Answer:

B 9, -9

Step-by-step explanation:

x^2 - 81 = 0

Add 81 to each side

x^2 = 81

Take the square root of each side

sqrt(x^2) = sqrt(81)

x = ±9

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Nothing can be done with this question!
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4 years ago
Help on this math question. 25 points.
solniwko [45]

Answer:

the third one

Step-by-step explanation:

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3 years ago
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-4z+1=bz+c solve for z
Angelina_Jolie [31]
-4z+1 = bz+c

Take all z's to one side
1 = bz+c+4z

Then take c to the other side
1-c = bz+4z

Factor out z on the right side
1-c = z(b+4)

Then divide (b+4) from both sides
z = 1-c/b+4 or (1-c)/(b+4)
6 0
3 years ago
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An automobile manufacturer has discovered that 20% of all the transmissions it installed in a particular style of truck are defe
Hatshy [7]

Answer:

0.148 = 14.8% probability that they will need to order at least one more new transmission

Step-by-step explanation:

For each transmission, there are only two possible outcomes. Either it is defective after a year of use, or it is not. The probability of a transmission being defective is independent of any other transmission. This means that the binomial probability distribution is used to solve this question.

Binomial probability distribution

The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}

In which C_{n,x} is the number of different combinations of x objects from a set of n elements, given by the following formula.

C_{n,x} = \frac{n!}{x!(n-x)!}

And p is the probability of X happening.

20% of all the transmissions it installed in a particular style of truck are defective after a year of use.

This means that p = 0.2

Sold seven trucks:

This means that n = 7

It has two of the new transmissions in stock. What is the probability that they will need to order at least one more new transmission?

This is the probability that at least 3 are defective, that is:

P(X \geq 3) = 1 - P(X < 3)

In which

P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2)

So

P(X = x) = C_{n,x}.p^{x}.(1-p)^{n-x}

P(X = 0) = C_{7,0}.(0.2)^{0}.(0.8)^{7} = 0.2097

P(X = 1) = C_{7,1}.(0.2)^{1}.(0.8)^{6} = 0.3670

P(X = 2) = C_{7,2}.(0.2)^{2}.(0.8)^{5} = 0.2753

P(X < 3) = P(X = 0) + P(X = 1) + P(X = 2) = 0.2097 + 0.3670 + 0.2753 = 0.852

P(X \geq 3) = 1 - P(X < 3) = 1 - 0.852 = 0.148

0.148 = 14.8% probability that they will need to order at least one more new transmission

6 0
3 years ago
Which point would map onto itself after a reflection across the line y = –x?
Rudiy27

Answer:

+x=-y

Step-by-step explanation:

5 0
3 years ago
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