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3 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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A submarine started at sea level and was 400 meters below sea level in 10 minutes.

ladessa [460]

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I believe the answer is C), as the answer for D) would be -40 meters per minute, but it's still 40. I'm not sure though, so it's either C) or D).

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2 years ago

A recipe that serves four people calls for 2 1/4 cups of butter. How many cups of butter needed to serve 10 people? Show your wo

Eduardwww [97]

Answer:

5 5/8

Step-by-step explanation:

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2 years ago

Divide.

slavikrds [6]

Answer:

(24y^3x-20y^5x^2)/(-3y^5x^2)

= y^3x(24-20y^2x))/(-3y^5x^2)

=(24-20y^2x)/(-3y^2x)

=(24/(-3y^2x))-((20y^2x)/(-3y^2x))

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2 years ago

What temperature is 20 degrees lower than 6 degree celsius

Hatshy [7]

The answer is -14 degrees centigrade

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3 years ago

PLEASE HELP ME!!!!!!!!!!!!!!!!!!! ASAP :)

Mashcka [7]

Answer:

c) The growth factor per days is 1.08

e) The growth factor per hour is 1.08^{1/24}

Step-by-step explanation:

Given the following data;

P(d) = 10 * 1.08^{d} in thousands.

a. To find the number of insects on day 1;

Day, d = 1

$P(d) = 10 * 1.08^{d}$ ......equation 1

Substituting into the formula, we have;

$P(1) = 10 * 1.08^{1}$

$P(1) = 10 * 1.08$

$P(1) = 10.08$

Therefore, option (a) and (b) are incorrect.

c. To find the growth factor per day;

An exponential function is given by the formula;

$y = mg^{x}$ .....equation 2

Where;

g is the growth factor of a population.

Comparing eqn 2 with eqn 1;

g = 1.08

Therefore, option (c) is correct.

e. To find growth factor per hour;

From equation 1 above;

$P(1) = 10 * 1.08^{\frac {1}{2}}$

Therefore, option e is correct.

4 0

2 years ago