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3 years ago

Find the 7th term of the geometric sequence a3 =128,r=-1/4

Mathematics

1 answer:

kenny6666 [7]3 years ago

7 0

Answer:

Step-by-step explanation:

The general formula for this sequence is a(n) = a(1)*(-1/4)^(n - 1). We don't yet know a(1).

If a(3) = 128, then 128 = a(1)*(-1/4)^(3 - 1), or

128 = a(1)*(1/16)

and so a(1) = 128/16

resulting in the specific formua a(n) = 8(-1/4)^(n - 1)

Now let's find a(7):

a(7) = 8(-1/4)^1 * (-1/4)^(6)

a(7) = 8(-1/4)^7

You might be interested in

What is the constant of proportionality in y=5x

-BARSIC- [3]

Answer:

Step-by-step explanation:

General equation of direct variation:

y = kx,

where k is the constant of proportionality.

In your case, you have

y = 5x, so 5 is the constant of proportionality.

8 0

2 years ago

The Bilbo Company plans to manufacture decals for children's lunchboxes. Each decal

Gwar [14]

Answer: 1 -2ax²+2x-ax

Step-by-step explanation:

Hi, to answer this question we have to apply the next formula:

Area of a rectangle: length x width

Replacing with the values given:

A = (2x+1) (1-ax)

A = [2x(1)] + [2x(-ax)] +[ 1(1)]+ [1 (-ax)]

A = 2x- 2ax² +1- ax

A = 1 -2ax²+2x-ax

In conclusion, the correct option is 1 -2ax²+2x-ax

Feel free to ask for more if needed or if you did not understand something.

4 0

3 years ago

What is the slope of the line that passes through the points (-10, -8) and

RoseWind [281]

Answer:

Equation: y = -4x + 32

Slope: -4

Step-by-step explanation:

Given : (-10,-8) and (-8, -16)

Slope Formula: $\frac{y_1 - y_2}{x_1-x_2}$

Solve For Slope, Input Given Points:

$\frac{-8 - (-16)}{-10 - (-8)}$
$\frac{8}{-2}$
$-4$

Solve for y-intercept:

Input the slope into the equation y = mx + b. Plugin x and y values for the x and y variables to find b.

y = -4x + b
-8 = -10(4) + b
-8 = -40 + b
b = 32

Equation of LIne: y = -4x + 32

-Chetan K

5 0

1 year ago

Read 2 more answers

Starting at the same point at the same time, Samuel and Heather rode their bikes in the same direction. Samuel traveled 3km/h fa

12345 [234]

Samuel was going with 40 km/h and Heather was going with 37 km/h

Step-by-step explanation:

Starting at the same point at the same time, Samuel and Heather rode their bikes in the same direction

Samuel traveled 3 km/h faster than Heather
After 3.5 h Samuel stopped for a half-hour break, but Heather kept going
Heather was 8 km ahead of Samuel

We need to find how fast each was going

Assume that Heather's speed is x km/h

∵ Heather's speed = x km/h

∵ Samuel traveled 3 km/h faster than Heather

∴ Samuel's speed = x + 3 km/h

The formula of the distance is distance = speed × time

∵ Samuel travel for 3.5 hours

- Find the distance that Samuel traveled in 3.5 h

∴ Samuel distance = (x + 3) × 3.5

- Multiply the bracket by 3.5 to simplify

∴ Samuel distance = 3.5x + 10.5

∵ Samuel took a break for half hour

∵ Heather kept going

∵ At the end of the break, Heather was 8 km ahead of Samuel

- That means Heather was going for 4 hours (3.5 + 0.5), and her

distance is longer than Samuel distance by 8 km

∴ Heather distance = x × 4 = 4x

- Subtract the distance of Samuel from the distance of Heather

and equate the difference by 8

∵ 4x - (3x + 10.5) = 8

∴ 4x - 3x - 10.5 = 8

- Add the like terms in the left hand side

∴ 0.5x - 10.5 = 8

- Add 10.5 to both sides

∴ 0.5x = 18.5

- Divide both sides by 0.5

∴ x = 37

∵ x represents Heather's speed

∴ Heather's speed = 37 km/h

∵ x + 3 represents Samuel's speed

∴ Samuel's speed = 37 + 3 = 40 km/h

Samuel was going with 40 km/h and Heather was going with 37 km/h

Learn more:

You can learn more about the equation of motion in brainly.com/question/568302

#LearnwithBrainly

3 0

3 years ago

Two side lengths of a triangle are 17 meters and 12 meter long. What is the range of possible lengths for the third side?

serious [3.7K]

Use a^2+b^2=c^2.
so u might have two answer one if u plug 17 and 12 as your a and b and solve for c
second is when you plug 12 as a and 17 as 17 qnd solve for b.
hope this helped

5 0

3 years ago