1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
nika2105 [10]
3 years ago
8

Find the sum of the first 8 terms of the sequence: -5. 15, -45, 135, .......

Mathematics
1 answer:
MakcuM [25]3 years ago
7 0
Sum of geometric sequence

for the sum where the initial value is a₁ and the common ratio is r and the term is n

S_n= \frac{a_1(1-r^n)}{1-r}

common ratio is -3
-5 times -3 is 15, -15 times -3=-45 etc
first term is -5
and we want the 8th term

S_8= \frac{-5(1-(-3)^8)}{1-(-3)}
S_8= \frac{-5(1-6561)}{1+3}
S_8= \frac{-5(-6560)}{4}
S_8= \frac{32800}{4}
S_8= 8200


the sum is 8200
You might be interested in
Which percent is equivalent to 0.3?<br> A. 0.003%<br> B. 0.03%<br> C. 3%<br> D. 30%
Kitty [74]

Answer:

D, 30%

Step-by-step explanation:

you move the decimal point twice to the right

8 0
3 years ago
Read 2 more answers
Kimmie wants to earn money by baking and selling cookies. She works up a business plan and finds her cost and revenue functions
vodka [1.7K]

Answer:

profit of 240

Step-by-step explanation:

credit to the person above me

7 0
3 years ago
A triangle has one leg measuring 10 inches and the hypotenuse measuring 20 inches. the other leg measures 10\sqrt[]{3} 10 3 inch
stiv31 [10]
From the description given for the triangle above, I think the type of triangle that is represented would be a right triangle. This type of triangle contains a right angle and two acute angles. In order to say or prove that it is a right triangle, it should be able to satisfy the Pythagorean Theorem which relates the sides of the triangle. It is expressed as follows:

c^2 = a^2 + b^2

 where c is the hypotenuse or the longest side and a, b are the two shorter sides.

To prove that the triangle is indeed a right triangle, we use the equation above.

c^2 = a^2 + b^2
c^2 = 20^2 = 10^2 + (10sqrt(3))^2
400 = 100 + (100(3))
400 = 400
5 0
3 years ago
Need Help fast, with steps
Hitman42 [59]

Answer:The solution is in the attached file below

Step-by-step explanation:

5 0
3 years ago
The circular blade on a saw has a diameter of 7.5 inches and rotates at 2400 revolutions per minute.
Archy [21]
For a:
    
       (2400*2*PI)/60(seconds) = 80 PI RAD/Sec

For b: 
   
        arc length s= radius r * central angle(in radians) 

                          = ((80*pi*7.5)/(2*pi)
                          =25


                          



4 0
3 years ago
Other questions:
  • The ratio of the volume of fruit juice to the volume of smoothies served at a party was 4 1/2: 2.4. There were 35 liters more fr
    9·1 answer
  • Write the equation of a line that is perpendicular to y=-2/7x+9 and passes through the point (4,-6)
    6·2 answers
  • A wedding dress was marked up 35% and is now selling for $270.00. What was the original price of the dress?
    12·2 answers
  • If a rope that is 29.7 inches long is cut into equal pieces that are 2.25 inches long, how many pieces of rope can be created
    10·2 answers
  • Mrs.fisher has 91 watches on display at her store. She says she can arrange them into rows and colums without any watch left ove
    8·1 answer
  • I need to solve for b but I don't know how
    10·1 answer
  • A nursery has 15 bags of soil each planter hold1/8 of a bag how many planters can be filled
    15·1 answer
  • Use the first five terms of the binomial theorem to approximate (-1.4)^8
    12·1 answer
  • You need to know the number of different arrangements possible for five distinct letters. You decide to use the permutations rul
    9·2 answers
  • Help PLease! PLease explainn how to do these types of equations!
    6·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!