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3 years ago

What are the real and complex solutions of the polynomial equation? x^4-41x^2=-400

Mathematics

1 answer:

tankabanditka [31]3 years ago

7 0

<h3>Answer:</h3>

The real solutions are -5, -4, 4, 5. There are no complex solutions.

<h3>Step-by-step explanation:</h3>

The equation ...

... x^4 -41x^2 +400 = 0

can be factored as ...

... (x^2 -16)(x^2 -25) = 0

... (x -4)(x +4)(x -5)(x +5) = 0

So, all roots are real and are ...

... x ∈ {-5, -4, 4, 5}

_____

These are the values of x that make the factors zero.

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Solve for x. 8/x-7=7/2

zloy xaker [14]

X= 9 2/7 ( the first answer is correct )

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3 years ago

Read 2 more answers

If cot x = .78, what is tan x

Vanyuwa [196]

We know, tan x = 1 / cot x
So,tan x = 1/ 0.78
tan x = 1.28

In short,Your Answer would be 1.28

Hope this helps!

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2 years ago

to arrive at 2000 liters of 60% saline solution the attendant has to mix a 90% and a 40% saline solution. How many liters of eac

CaHeK987 [17]

Answer:

<u>800 liters</u> of 90% saline solution and <u>1200 liters</u> of 40% saline solution should be used.

Step-by-step explanation:

Given:

At 2000 liters of 60% saline solution the attendant has to mix a 90% and a 40% saline solution.

Now, to find the number of liters of saline solution each should be used.

<u><em>Let the liters of 90% saline solution mix be </em></u> $x.$ <u><em /></u>

<u><em>And let the liters of 40% saline solution mix be</em></u> $y.$

So, the total number of liters:

$x+y=2000.$

$y=2000-x\ \ \ ....(1)$

Now, the total percentage of saline solution:

$90\%\ of\ x+40\%\ of\ y=60\%\ of\ 2000$

$\frac{90}{100}\times x+\frac{40}{100}\times y=\frac{60}{100}\times 2000$

$0.9x+0.4y=1200$

Substituting the value of $y$ from equation (1) we get:

$0.9x+0.4(2000-x)=1200$

$0.9x+800-0.4x=1200$

$0.5x+800=1200$

Subtracting both sides by 800 we get:

$0.5x=400$

Dividing both sides by 0.5 we get:

$x=800.$

<u>The liters of 90% saline solution mix = 800.</u>

Now, substituting the value of $x$ in equation (1) to get the liters of 40% saline solution:

$y=2000-x$

$y=2000-800$

$y=1200.$

<u>Thus, the liters of 40% saline solution = 1200.</u>

Therefore, 800 liters of 90% saline solution and 1200 liters of 40% saline solution should be used.

8 0

3 years ago

Monica bought a sweater for $48.00. A week later the sweater went on sale for 25% off the original price. If Monica needed to pa

IRINA_888 [86]

Answer:

A $12.84

Step-by-step explanation:

Sweater was originally $48.00 before tax. $48.00 x 7% tax rate (.07) = $3.36 in tax

So the sweater originally would've cost $48.00 + $3.36 = $51.36

The sale price was 25% off the $48.00. $48.00 x 25% (.25) = $12.00

Then you subtract the $12.00 from the $48.00 to get the new price of $36.00

Now that's before tax, so $36.00 x 7% tax rate (.07) = $2.52 in tax

So the sweater would cost on sale $36.00 + $2.52 = $38.52

To figure out how much she would've saved you subtract the sale price & tax from the original price & tax $51.36 - $38.52 = $12.84

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2 years ago

What is the dilation for the transformation below?

lys-0071 [83]

Answer:

The dialation is of 2

Step-by-step explanation:

QR = 3 units

QS = 2 units

RS = 2 units

Q'R' = 6 units

Q'S' = 4 units

R'S' = 4 units

So as you can see, this triangle has doubled it's size, since it has been multiplied by 2.

Hope this helped!

Have a supercalifragilisticexpialidocious day!

4 0

3 years ago