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3 years ago

Anna made an error in determining the polynomial equation of smallest degree whose roots are -4,-2, -

Mathematics

1 answer:

nalin [4]3 years ago

8 0

Answer:

See explanation

Step-by-step explanation:

Ana started the work nicely by multiplying out factors to get:\

$(x+4)(x+2)(2x+1)(x-2)=0$

She multiplied $(x+2)(x-2)$ correctly using difference of two squares to get: $x^2-4$

Unfortunately: She made a mistake in multiplying $(x+4)(2x+1)$ she mistakenly got $x^2+9x+4$ instead of $2x^2+9x+4$ . She left out the coefficient of 2.

Therefore the second step should have been:

$(x^2-4)(2x^2+9x+4)$

The next step will now be:

$2x^4+9x^3+4x^2-8x^4-36x-16=0$

This simplifies to

$2x^4+9x^3-x^4-36x-16=0$

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If the area of a rectangle is 12cm2 what could its length be and its width?

lawyer [7]

Hello,

We know that th formula for the area of a rectangle is: $A=b*h$
Now, the problem in this excercise is that there is no restriction on the values that b and h can take, so, they can take any value provided that it meets: $b*h=12 cm^{2}$
for example:
$lenght= \frac{12}{3}cm \,\,\,\,\,\,and\,\,\,\,width= 3 cm \\ \\ A=\frac{12}{3}cm*3cm \\ A=12 cm^{2}$

But if they can only take intenger values, what we have to do is to descompose 12, and then we can analyze the possible solutions.

12 | 2
6 | 2
3 | 3
1

12= 2 *2*3

first option:
12=4*3

Answer: lenght= 4cm and width= 3cm or vice versa

second option:
12=2*6

Answer: lenght= 6cm and width= 2cm or vice versa

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3 years ago

Which expression is equivalent to 1/5 divided by 1/2?

anygoal [31]

Answer B! Hope this helps

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3 years ago

The number A of tablet computers sold (in millions) can be modeled by the function A=4.5t2+43.5t+17 , where t represents the num

Rina8888 [55]

The problem indicates that A represents the number of tablet computers sold in millions. So, if 65 million were sold, we must substitute A = 65 to the equation. Then, we find for t.

65 = 4.5t² +43.5t + 17
Solving for t using a calculator,
t = 1 and -10.67

Let's take the positive root. So, t=1.
That means the year would be 1 year after 2010. Therefore, the answer is 2011.

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2 years ago

What is the percentage of sugar in the syrup made of 10kg of water and 5kg of sugar? Hi and have a good day :D

arsen [322]

Answer:

33.33%

Step-by-step explanation:

the syrup has a total of 15kg of ingredients, 5kg of it is sugar, so 15/5 which will end as 33.33%

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2 years ago

Read 2 more answers

Find the quotient and any excluded values. (x + 5/x^2 + 9x + 20)/(x^2-16/x-4)

Wittaler [7]

By (x + 5/x^2 + 9x + 20) you apparently meant the following:

x+5
----------------------
x^2 + 9x + 20

and by

(x^2-16/x-4)
x^2-16
you apparently meant ---------------
x - 4

Please use additional parentheses for clarity.

Dividing,

 x+5 (x-4)(x+4)
---------------------- * ---------------
x^2 + 9x + 20 x-4

Now, x^2 + 9x + 20 factors into (x+4)(x+5), so what we have now is

(x+5)(x+4)
------------------------- = 1 This is true for all x, so there are no exclusions.
(x+4)(x+5)

3 0

3 years ago