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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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I round to 900 I have twice as many hundreds as ones and all my digits are different but their sums are 18 can someone answer th

stellarik [79]

Answer:

The number of once is 9.1

The number of hundreds is 8.9

Step-by-step explanation:

Given as :

The total of digits having ones and hundreds = 900

The sum of digits = 18

Let The number of ones digit = O

And The number of hundreds digit = H

So, According to question

H + O = 18 .........1

100 × H + 1 × O = 900 ........2

Solving the equation

( 100 × H - H ) + ( O - O ) = 900 - 18

Or, 99 H + 0 = 882

Or , 99 H = 882

∴ H = $\frac{882}{99}$

I.e H = 8.9

Put the value of H in eq 1

So, O = 18 - H

I.e O = 18 - 8.9

∴ O = 9.1

So, number of once = 9.1

number of hundreds = 8.9

Hence The number of once is 9.1 and The number of hundreds is 8.9

Answer

4 0

2 years ago

Miyoko's goal is to earn more than \$950$950dollar sign, 950 this week. She earns \$250$250dollar sign, 250 for every day she wo

GrogVix [38]

$250 c+ $ 180 g > $ 950

<u>Step-by-step explanation:</u>

As a cryptographer (c), Miyoko earns per day = $ 250

As a geologist (g) , Miyoko earns per day = $ 180

So the equation comes to be $250 c+ $ 180 g = $ 950

The equation can be rewritten to find c as, (950-180 g) / 250

The equation can be rewritten to find g as, (950 - 250 c) / 180

Plugin different values of c and g in the above 2 equations, we can find that ,

To achieve the goal, Miyoko requires to be a geologist for 3 days and crpytographist for 2 days.

5 0

2 years ago

U Get 73 pts !!CAN I PLS GET HELP !!!!Cassandra calculated the total volume of the figure below. A rectangular prism has a lengt

Arlecino [84]

Answer:

1.She used square units instead of cubic units.

2.In calculating the volume of the pyramid, she did not multiply by 1/3.

4.She subtracted the pyramid volume instead of adding it.

Step-by-step explanation:

because i got it right on my test.

8 0

2 years ago

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A spinner with 4 colors is spun for a total of 50 trials. Yellow was selected 10 times. What is the experimental probability of

Gnom [1K]

Answer:

Step-by-step explanation:

i did it

8 0

1 year ago

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Bernardo and Ogechi were asked to find an explicit formula for the sequence 1\,,\,8\,,\,64\,,\,512,...1,8,64,512,...1, comma, 8,

MatroZZZ [7]

Answer:

$h_{n}=1.(8)^{n-1}$ will be the correct formula for the given sequence.

Step-by-step explanation:

The given sequence is 1, 8, 64, 512...........

The given sequence is a geometric sequence having a common ratio (r) of

r = $\frac{\text{Second term}}{\text{First term}}$

r = $\frac{8}{1}=8$

Since explicit formula of a geometric sequence is given by

$T_{n}=a(r)^{n-1}$

where $T_{n}$ = nth term of the sequence

a = first term of the sequence

r = common ratio of the successive term to the previous term

Now we plug values of a and r in the formula to get the explicit formula for the given sequence.

$T_{n}=1.(8)^{n-1}$

Therefore, if Bernardo is saying that the formula of the sequence is

h(n) = $1.(8)^{n-1}$ then he is correct.

7 0

2 years ago

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