URGENT TEST PLEASE HELP

Mathematics

2 answers:

IceJOKER [234]4 years ago

8 0

John's gift cost 9 dollars

inysia [295]4 years ago

4 0

Fidget Spinners would cost around $1

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The cost for new carpet is $8.55 per square yard,plus an installation fee. If 700 square yards of carpet cost $6164 after instal

8090 [49]

$8,805.71 because 700=6164 which means 1000=8,805.71 by Multiplying 1000×6164 which equals 6,164,000 and this result you decide by 700

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4 years ago

Which is the following is the same as 2,088 feet per minute

Thepotemich [5.8K]

2,088÷60=24.8
24.8 feet per sec

8 0

3 years ago

What error was made? -4(6 - b) = 4 -24 - 4b = 4 -4b = 28 b = -7

lisov135 [29]

Answer:

step 2; a negative times a negative = a positive.

Step-by-step explanation:

-4(6-b)=4

-24 +4b=4

4b=28

b=7

3 0

3 years ago

Can anyone help me solve this? Please and thank you!

AveGali [126]

It's the sum of a geometric sequence.

Let's rewrite it a bit:

$\displaystyle\\\sum_{n=1}^{10}8\left(\dfrac{1}{4}\right)^{n-1}=8\sum_{n=1}^{10}\left(\dfrac{1}{4}\right)^n\cdot \left(\dfrac{1}{4}\right)^{-1}=8\sum_{n=1}^{10}\left(\dfrac{1}{4}\right)^n\cdot 4=32\sum_{n=1}^{10}\left(\dfrac{1}{4}\right)^n$

And now let's calculate this sum $\displaystyle \sum_{n=1}^{10}\left(\dfrac{1}{4}\right)^n$ :

$S_n=\dfrac{a(1-r^n)}{1-r}\\\\a=\dfrac{1}{4}\\n=10\\r=\dfrac{1}{4}\\\\S_{10}=\dfrac{\dfrac{1}{4}\cdot\left(1-\left(\dfrac{1}{4}\right)^{10}\right)}{1-\dfrac{1}{4}}=\dfrac{\dfrac{1}{4}\cdot\left(1-\dfrac{1}{1048576}\right)}{\dfrac{3}{4}}=\dfrac{\dfrac{1048575}{1048576}}{3}=\dfrac{1048575}{3145728}=\\=\dfrac{349525}{1048576}$