Find an equation for the nth term of the arithmetic sequence. a18 = 97, a20 = 281

I’ll give the Brainliest to whoever answers this question with a reasonable explanation.

SVEN [57.7K]

a) 0-32000
1-30000
2-28000
3-26000
4-24000
b)y=-2000x+32000
c) 16 min

7 0

3 years ago

Calling all mathemeticians

MAVERICK [17]

Wouldn’t be a,or d. I would honestly say B..

4 0

3 years ago

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Need some math help!!! <br> Factor the polynomial by grouping: 12p^3 − 21 p^2 + 28p − 49

Andru [333]

Answer:

$\left(4p-7\right)\left(3p^2+7\right)$

Step-by-step explanation:

$12p^3-21p^2+28p-49$

$\left(12p^3-21p^2\right)+\left(28p-49\right)$

$7\left(4p-7\right)$

$3p^2\left(4p-7\right)$

$7\left(4p-7\right)+3p^2\left(4p-7\right)$

$\left(4p-7\right)\left(3p^2+7\right)$

8 0

3 years ago

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Turn -3/11 into a decimal

lutik1710 [3]

-0.272727272727272727272727272727

4 0

3 years ago

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Determine which of the lines are parallel and which of the lines are perpendicular. Select all of the statements that are true.

slega [8]

Answers:

Line A is parallel to line D.

Line A is perpendicular to line C.

Line C is perpendicular to line D.

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Explanation:

Let's use the slope formula to calculate the slope of the line through (-1,-17) and (3,11)

$(x_1,y_1) = (-1,-17) \text{ and } (x_2,y_2) = (3,11)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{11 - (-17)}{3 - (-1)}\\\\m = \frac{11 + 17}{3 + 1}\\\\m = \frac{28}{4}\\\\m = 7\\\\$

The slope of line A is 7

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Now let's find the slope of line B.

$(x_1,y_1) = (0,4) \text{ and } (x_2,y_2) = (7,-5)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{-5 - 4}{7 - 0}\\\\m = -\frac{9}{7}\\\\$

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Now onto line C.

$(x_1,y_1) = (7,1) \text{ and } (x_2,y_2) = (0,2)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{2 - 1}{0 - 7}\\\\m = \frac{1}{-7}\\\\m = -\frac{1}{7}\\\\$

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Lastly we have line D.

$(x_1,y_1) = (-1,-6) \text{ and } (x_2,y_2) = (1,8)\\\\m = \frac{y_{2} - y_{1}}{x_{2} - x_{1}}\\\\m = \frac{8 - (-6)}{1 - (-1)}\\\\m = \frac{8 + 6}{1 + 1}\\\\m = \frac{14}{2}\\\\m = 7\\\\$

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Here's a summary of the slopes we found

$\begin{array}{|c|c|} \cline{1-2}\text{Line} & \text{Slope}\\\cline{1-2}\text{A} & 7\\\cline{1-2}\text{B} & -9/7\\\cline{1-2}\text{C} & -1/7\\\cline{1-2}\text{D} & 7\\\cline{1-2}\end{array}$

Recall that parallel lines have equal slopes, but different y intercepts. This fact makes Line A parallel to line D.

Lines A and C are perpendicular to one another, because the slopes 7 and -1/7 multiply to -1. In other words, -1/7 is the negative reciprocal of 7, and vice versa. These two lines form a 90 degree angle.

Lines C and D are perpendicular for the same reasoning as the previous paragraph.

Line B unfortunately is neither parallel nor perpendicular to any of the other lines mentioned.

You can use a graphing tool like Desmos or GeoGebra to verify these answers.

6 0

1 year ago