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3 years ago

5

Last year, Erin earned $1,497.75. This year, she earned 2.9 times as much as last year. Which of the following answer choices is

the most reasonable estimate for the amount of money Erin earned this year?
$2,000

$3,000

$4,500

$6,000

1 answer:

Ne4ueva [31]3 years ago

8 0

I believe it is 4,500 because that is the closest to my answer of about 4400

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Please help me I need to pass

laila [671]

I'll pick B Hope this helps

7 0

4 years ago

____ [38]

Answer:

Please check the explanation.

Step-by-step explanation:

Given

f(x) = 3x + x³

Taking differentiate

$\frac{d}{dx}\left(3x+x^3\right)$

$\mathrm{Apply\:the\:Sum/Difference\:Rule}:\quad \left(f\pm g\right)'=f\:'\pm g'$

$=\frac{d}{dx}\left(3x\right)+\frac{d}{dx}\left(x^3\right)$

solving

$\frac{d}{dx}\left(3x\right)$

$\mathrm{Take\:the\:constant\:out}:\quad \left(a\cdot f\right)'=a\cdot f\:'$

$=3\frac{d}{dx}\left(x\right)$

$\mathrm{Apply\:the\:common\:derivative}:\quad \frac{d}{dx}\left(x\right)=1$

$=3\cdot \:1$

$=3$

now solving

$\frac{d}{dx}\left(x^3\right)$

$\mathrm{Apply\:the\:Power\:Rule}:\quad \frac{d}{dx}\left(x^a\right)=a\cdot x^{a-1}$

$=3x^{3-1}$

$=3x^2$

Thus, the expression becomes

$\frac{d}{dx}\left(3x+x^3\right)=\frac{d}{dx}\left(3x\right)+\frac{d}{dx}\left(x^3\right)$

$=3+3x^2$

Thus,

f'(x) = 3 + 3x²

Given that f'(x) = 15

substituting the value f'(x) = 15 in f'(x) = 3 + 3x²

f'(x) = 3 + 3x²

15 = 3 + 3x²

switch sides

3 + 3x² = 15

3x² = 15-3

3x² = 12

Divide both sides by 3

x² = 4

$\mathrm{For\:}x^2=f\left(a\right)\mathrm{\:the\:solutions\:are\:}x=\sqrt{f\left(a\right)},\:\:-\sqrt{f\left(a\right)}$

$x=\sqrt{4},\:x=-\sqrt{4}$

$x=2,\:x=-2$

Thus, the value of x will be:

$x=2,\:x=-2$

5 0

3 years ago

11/2 as mixed numbers?<br> PLEASEE help

ra1l [238]

Answer: 5 1/2

Step-by-step explanation:

8 0

1 year ago

Read 2 more answers

A cylindrical cardboard mailing tube has a diameter of 5 in. and a height of 30 in. A total of 30% of the tube’s capacity is fil

olga2289 [7]

First is to get the volume of the cylinder.
Volume = pi * r^2 * H
Volume = 3.1416 * (5/2)^2 * 30
Volume = 589.05 in^3

30% is already filled.
Filled Space = 589.05 * 0.30
Filled Space = 176.715 in^3
Empty Space = 412.335 in^3

Next, get the volume of the sphere.
V = (4/3)*pi*r^3
V = (4/3)*pi*(0.6/2)^3
V = 0.1130976 in^3

Number of foams = Filled Space / V
Number of foams = 176.715 / <span>0.1130976
Number of foams = 1562 Foams</span>

5 0

3 years ago

Jamarius buys T-shirts for $6 each and marks up the price by 45%. How much profit does Jamarius make from each T-shirt sold?

3241004551 [841]

Answer:

$2.70

Step-by-step explanation:

To add 45 percent to the original price you do 100%+45%=145%=1.45

times 1.45 by the original price.

Then take away the original price from the answer you just got.

$1.45×$6=$8.70

$8.70-$6=$2.70

6 0

3 years ago