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3 years ago

2d+4=10+5d d= what does it equal?

Mathematics

1 answer:

zepelin [54]3 years ago

8 0

Answer:

d = -2

Step-by-step explanation:

2d + 4 = 10 + 5d

2d - 2d + 4 = 10 + 5d - 2d

4 = 10 + 3d

4 - 10 = 10 - 10 + 3d

-6 = 3d

(1/3) -6 = 3d (1/3)

-2 = d

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Creating and solving formulas for geometric series:mastery test

Levart [38]

Answer:

D. $y = 5\cdot \Sigma_{i=0}^{4} \left(\frac{1}{3} \right)^{i}$

Step-by-step explanation:

Let be $y = \Sigma_{i = 0}^{4} \left[5\cdot \left(\frac{1}{3} \right)^{i}\right]$ . To find the equivalent expression we must use the following property:

$y = c\cdot \Sigma_{i = 0}^{n} p(x) = \Sigma_{i=0}^{n} [c\cdot p(x)]$ (1)

Based on this fact, we find the following equivalence:

$y = 5\cdot \Sigma_{i=0}^{4} \left(\frac{1}{3} \right)^{i}$

Hence, the correct answer is D.

6 0

3 years ago

Problem page the price of a notebook has dropped to $3.20 today. Yesterday's price was $3.45 . Find the percentage decrease. Rou

Anna11 [10]

Yesterday's price of notebook = $3.45

Today's price of notebook = $3.20

We have to determine the percentage decrease in the cost of notebook.

Percentage decrease = (Decrease $\div$ Old price) $\times 100$

So, percentage decrease = $\frac{3.45-3.20}{3.45} \times 100$

= $\frac{0.25}{3.45} \times 100$

= 7.246%

= 7.25%

Therefore, there is 7.25% of decrease in the cost of the notebook.

8 0

3 years ago

webassign If a snowball melts so that its surface area decreases at a rate of 6 cm2/min, find the rate at which the diameter dec

drek231 [11]

Answer:

The answer is $\frac{3}{10\pi } cm/min$

Step-by-step explanation:

Assuming the snowball is a perfect sphere, then if A denotes the surface area and D the diameter then:

$A=4\pi r^{2} = 4\pi (\frac{D}{2} )^{2} =\pi D^{2}$

Differentiating wrt r we have:

$\frac{dA}{dD} =2\pi D$

We are told that $\frac{dA}{dt}= -6$ and we want to find $\frac{dD}{dt}$

By the chain rule we have:

$\frac{dA}{dD}=\frac{dA}{dt}.\frac{dt}{dD}=\frac{\frac{dA}{dt} }{\frac{dD}{dt} }$

∴ $2\pi D=-\frac{6}{\frac{dD}{dt} }$

∴ $\frac{dD}{dt}=-\frac{6}{2\pi D}$

When D=10 then

$\frac{dD}{dt} =-\frac{6}{10*2\pi } =-\frac{3}{10\pi }$

The sign (-) shows that the D is decreasing.

3 0

3 years ago

What is 22/9 as a mixed number

sergiy2304 [10]

If you do 22÷9 and see the hole number: 2. Then do 2 x 9 and you get 18. Now do 22-18 and you get 4. So do 2 4/9. Always have the denominator stay the same.

5 0

4 years ago

Read 2 more answers

Need help please and thank you

vekshin1

We can drop the absolute value and the signs, and the integer part if they're all the same, and then make a common denominator and check for a decreasing sequence.

10/12, 7/12, 5/12 -- Check decreasing

3 1/3, 3 2/3, 2 2/3 -- nope, increases then decreases

6 5/7, 6 3/7, 5 2/7 - Check, decreasing

11 7/10, 11 6/10, 10 3/10 -- Check, decreasing

Answer: A,C,D

8 0

3 years ago