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3 years ago

What is the sum of the first five terms of a geometric series with A1 equals 20 and R equals 1/4

Mathematics

1 answer:

sweet-ann [11.9K]3 years ago

6 0

Sum = 20(1-(1/4)^5) / (1-1/4) = 26.64

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What are the zeros of f(x) = x2 - x - 20?

sattari [20]

Answer:

(-4,0) and (5,0)

Step-by-step explanation:

Factor.

f(x) = x^2 -x - 20

Factors of -20 that when are added they equal -1

-5 and 4

(x-5) (x+4)

x=5 and x=-4

5 0

3 years ago

CAN SOMEONE PLEASE HELP ME. I NEED HELP ON THIS QUESTION

sleet_krkn [62]

Answer:

a segment cd only

Step-by-step explanation:

segment cd is the only line that passes through segment ab at a right angle

4 0

3 years ago

Given the domain (-2,2,4) what is the range for the relation 3x-y=3

Bumek [7]

Answer:

Given the domain, the range for 3x-y = 3 is {-9, 6, 9}

Step-by-step explanation:

First you have to put the relation in terms of y ⇒ 3x - y = 3⇒ 3x -3 = y

⇒ y = 3x - 3.

Then you replace the values indicated by the domain to find their "y" values (the ones that constitute the range).

f(-2) = -9

f(2) = 6

f(4) = 9.

Finally, the range for the given domain is {-9, 6, 9}

3 0

3 years ago

Assume you have such a watch. if a minimum of 18.0% of the original tritium is needed to read the dial in dark places, for how m

laila [671]

Given that the half life of 3H is 12.3 years.

The amount of substance left of a radioactive substance with half life of $t_{ \frac{1}{2} }$ after t years is given by

$N(t)=N_0\left(\frac{1}{2} \right)^{ \frac{t}{t_{\frac{1}{2}} }$

Therefore, the number of years it will take for 18% of the original tritinum to remain is given by

$18 \% = 100 \% \left(\frac{1}{2} \right)^{ \frac{t}{12.3}} \\ \\ \Rightarrow\left(\frac{1}{2} \right)^{ \frac{t}{12.3}} =0.18 \\ \\ \Rightarrow\frac{t}{12.3}\ln\left(\frac{1}{2} \right)=\ln0.18 \\ \\ \Rightarrow\frac{t}{12.3}= \frac{\ln0.18}{\ln\left(\frac{1}{2} \right)} = \frac{-1.715}{-0.6931} =2.474\\ \\ \Rightarrow t=2.474(12.3)=30.4$

Therefore, the number of <span>years that the time could be read at night is 30.4 years.</span>

5 0

3 years ago

At Davis you can buy 12 pounds of M&M's for $12.24 or 8 pounds for $8.24 at Smith's. Which is the better buy

Law Incorporation [45]

Answer:

12 pounds

Explanation:

If you were to divide 12.24 from 12 you would get 1.02, which would be the cost of each pound.

Meanwhile, if you were to divide 8.24 from 8 you would get 1.03, which would be the cost of each pound.

So although its only a 1 cent difference and you are technically spending more by buying the 12 pounds, if it were to buy 8 pounds from the cost of each pound for the 12 pounds, you'd only be spending $8.16 vs $8.24.

Because you would multiply 1.02, which is the cost of each pound for 12, by 8 and you would get 8.16.

4 0

2 years ago