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2 years ago

For what value of "a" will the product shown below have a purely imaginary value? (Show work please)

1 answer:

5 0

If you expand out the brackets you get this,

(4+5i)(a+2i) = 4a + (5a)i + 8i - 10

The -10 comes from 5i * 2i.
Squaring i becomes -1.

Let's group the real stuff together,
and imaginary separately,

(4a - 10) + (5a + 8)i

For this to be purely imaginary,
the real part needs to be zero.

Therefore 4a - 10 = 0

Solve for a.

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Which equation represents the line shown on the graph?

Mama L [17]

Hello there,

To find out the equation you use the slope intercept form...

y = mx + b

M is the slope and b is where the line crosses the y-axis...

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The distance from (0,2) to (1,5) is 3 units up and 1 unit over.

So the correct answer should be...

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8 0

2 years ago

-6/5-2/5v+4/15+1/3v please help

PtichkaEL [24]

Answer:

-14/15-1/15v

Step-by-step explanation:

First you make all of the fractions have the common denominator 15.

And then you have -18/15-6/15v+4/15+5/15v

Then you combine like terms to get -14/15-1/15v

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2 years ago

It is claimed that 55% of marriages in the state of California end in divorce within the first 15 years. A large study was start

kykrilka [37]

Answer:

0.0045 = 0.45% probability that less than two of them ended in a divorce

Step-by-step explanation:

For each marriage, there are only two possible outcomes. Either it ended in divorce, or it did not. The probability of a marriage ending in divorce is independent of any other marriage. 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.

55% of marriages in the state of California end in divorce within the first 15 years.

This means that $p = 0.55$

Suppose 10 marriages are randomly selected.

This means that $n = 10$

What is the probability that less than two of them ended in a divorce?

This is

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

In which

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

$P(X = 0) = C_{10,0}.(0.55)^{0}.(0.45)^{10} = 0.0003$

$P(X = 1) = C_{10,1}.(0.55)^{1}.(0.45)^{9} = 0.0042$

$P(X < 2) = P(X = 0) + P(X = 1) = 0.0003 + 0.0042 = 0.0045$

0.0045 = 0.45% probability that less than two of them ended in a divorce

8 0

1 year ago

Emma needs to divide 7 by 1/2. Which strategy can Emma use to get the answer?

Juliette [100K]

Answer:

Step-by-step explanation:

Convert the fraction into a decimal

1/2 = 0.5

Divide

7/0.5 = 14

7 0

2 years ago

The correlation coefficient for the ages of drivers in a driver safety class and the number of traffic violations they have rece

Doss [256]

A correlation coefficient is always a value in between -1 and 1
The closest a coefficient to -1, the correlation is a strong negative correlation
The closest a coefficient to 1, the correlation is a strong positive correlation
The closest a coefficient to 0, there is no correlation at all

The coefficient -0.61 shows a strong negative correlation
This means that the relationship between the age and the violation is an inverse relationship; as age increases, violation decreases

Answer: option C

7 0

2 years ago