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2 years ago

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I don’t understand about this question

1 answer:

Alja [10]2 years ago

7 0

Answer:

Domain

Step-by-step explanation:

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Calculate the arithmetic sequence in which a9=17 and the common difference is d=-2.1

jek_recluse [69]

Answer:

$S_{31}=71.3$

Step-by-step explanation:

The nth term of an arithmetic sequence is given by the formula,

$U_n=a_1+(n-1)d$

We were given that the 9th term is $17$ .

$\Rightarrow 17=a_1+(9-1)(-2.1)$

$\Rightarrow 17=a_1+(8)\times(-2.1)$

$\Rightarrow 17=a_1-\frac{84}{5}$

$\Rightarrow 17+\frac{84}{5}=a_1$

$\Rightarrow a_1=\frac{169}{5}$

The sum of the first n-terms is given by the formula,

$S_n=\frac{n}{2}(2a_1+(n-1)d)$

To find $S_{31}$ , we substitute $n=31$ , $a_1=\frac{169}{5}$ and $d=-2.1$ .

$\Rightarrow S_{31}=\frac{31}{2}(2(\frac{169}{5}+(31-1)(-2.1))$

$\Rightarrow S_{31}=\frac{31}{2}(2(\frac{169}{5}+(30)(-2.1))$

$\Rightarrow S_{31}=\frac{31}{2}(\frac{23}{5})$

$\Rightarrow S_{31}=\frac{713}{10}$

$\Rightarrow S_{31}=71.3$

The correct answer is D

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3 years ago

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lbvjy [14]

Move the decimal point 2 places to the left answer: 0.0951

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Could anyone help with this, im terrible at geometry haha

bekas [8.4K]

Answer:

10.90⁰

11.126⁰

12.54⁰

13.180⁰

Step-by-step explanation:

CDE is 180⁰ because it is a straight line

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2 years ago

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A salesman sold twice as much pears in the afternoon than in the morning. If he sold 360 kilograms of pears that day, how many k

serg [7]

Answer: 240 kg

Step-by-step explanation: Divide 360 by 3. That would equal 120. 120 times 2 equals 240

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3 years ago

Hamburger sells for 3 pounds for 6$. If Samantha buys 10 pounds of hamburger, how much will she pay?

Afina-wow [57]

She will pay 20$ for 10 pounds of hamburger

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