2-√-9 a.) 2-3i b.) 2-4=-1 c.) 2+3=5 d.) 2+3i

A bakery is offering a promotion where a customer can buy a dozen cookies for $10.00. Normally, the cookies cost $1.15 each. By

jenyasd209 [6]

Answer:

28%

Step-by-step explanation:

The result is about 27.5362% so if we round it it will be 28%

5 0

3 years ago

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A person is 89-93 pounds depending on the day, 13 years old, and 5 foot tall. Is this an appropriate weight?

kenny6666 [7]

Answer:

I don't think so cause average in my town is 100 to 109

6 0

3 years ago

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The altitude of a triangle is increasing at a rate of 1.500 centimeters/minute while the area of the triangle is increasing at a

puteri [66]

Answer:

The base of the triangle is shrinking at a rate of $\frac{131}{32}$ centimeters per minute.

Step-by-step explanation:

The formula of the area of a triangle is given by the following expression:

$A = \frac{1}{2}\cdot b \cdot h$

Where:

$A$ - Area of the triangle, measured in square centimeters.

$b$ - Base of the triangle, measured in centimeters.

$h$ - Height of the triangle, measured in centimeters.

The base of the triangle is:

$b = \frac{2\cdot A}{h}$

If $A = 98000\,cm^{2}$ and $h = 8000\,cm$ , the base of the triangle is:

$b = \frac{2\cdot (98000\,cm^{2})}{8000\,cm}$

$b = 24.5\,cm$

The rate of change of the area of the triangle in time, measured in minutes, is obtained after differentiating by rule of chain and using deriving rules:

$\frac{dA}{dt} = \frac{1}{2}\cdot h\cdot \frac{db}{dt} + \frac{1}{2}\cdot b \cdot \frac{dh}{dt}$

$\frac{dA}{dt} = \frac{1}{2} \cdot \left(h\cdot \frac{db}{dt}+b \cdot \frac{dh}{dt} \right)$

The rate of change of the base of the triangle is now cleared:

$2\cdot \frac{dA}{dt} = h\cdot \frac{db}{dt} + b\cdot \frac{dh}{dt}$

$h\cdot \frac{db}{dt} = 2\cdot \frac{dA}{dt}-b\cdot \frac{dh}{dt}$

$\frac{db}{dt} = \frac{2\cdot \frac{dA}{dt} - b \cdot \frac{dh}{dt} }{h}$

Given that $\frac{dA}{dt} = 2000\,\frac{cm^{2}}{min}$ , $b = 24.5\,cm$ , $\frac{dh}{dt} = 1500\,\frac{cm}{min}$ and $h = 8000\,cm$ , the rate of change of the base of the triangle is:

$\frac{db}{dt} = \frac{2\cdot \left(2000\,\frac{cm^{2}}{min} \right)-(24.5\,cm)\cdot \left(1500\,\frac{cm}{min} \right)}{8000\,cm}$

$\frac{db}{dt} = -\frac{131}{32}\,\frac{cm}{min}$

The base of the triangle is shrinking at a rate of $\frac{131}{32}$ centimeters per minute.

5 0

3 years ago

What polynomial has roots of -5,-4 and 1

Semenov [28]

x³ + 8x² + 11x - 20 ← the first on list

given the roots of a polynomial, say x = a, x = b and x = c

then the factors are (x - a), (x - b) and (x - c)

the polynomial is the product of the factors

f(x) = (x - a)(x - b)(x - c)

here x = - 5, x = - 4 and x = 1, hence factors are

(x + 5), (x + 4) and (x - 1)

f(x) =(x + 5)(x + 4)(x - 1) ← expanding factors gives

f(x) = (x² + 9x + 20)(x - 1) = x³ + 8x² + 11x - 20

7 0

4 years ago

Two companies in town sell gravel. Company A sells it for 11 cents a cubic foot. Company B sells it for 3 dollars a cubic yard.

Tpy6a [65]

Company B because if u multiply 20×3 then you would only have to pay $60 and if u buy it from company A you would have to multiply 11×3 and then multiply 33× 20 and then you would have to pay $660 so u would save more with company B

5 0

3 years ago

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