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
mariarad [96]
3 years ago
15

What is the some need help????​

Mathematics
1 answer:
snow_tiger [21]3 years ago
5 0

The sum formula for a geometric sequaence is:

sum(n) = a1(1-r^n)/1-r

Where n is the number of terms, a1 is the first term and r is the common ratio:

s(8) = 3(1-1/2^8) / (1-1/2)

s(8) = 3(1-1/256) / 1/2

s(8) = 2 253/256 / 1/2

s(8) = 765/128

The answer is C.

You might be interested in
Select the decimal that is equivalent to<br> 57<br> 220
Umnica [9.8K]

Answer:

2.5909090909

Step-by-step explanation:

4 0
3 years ago
Charlene bought a used.It cost $43.00.A new skateboard costs 3 times as much as the used one Charlene bought.How much does a new
vovangra [49]
Multiply it by 3.
43.00*3=129=priceNewSkateboard
6 0
3 years ago
A chemist has three different acid solutions. The first acid solution contains 25 % acid, the second contains 45 % and the third
liq [111]

Answer:

Wyzant

ALGEBRA WORD PROBLEM

Dorian S. asked • 06/28/17

THREE LINEAR EQUATIONS WITH THREE VARIABLES

A chemist has three different acid solutions. The first acid solution contains 15% acid, the second contains 25%,

and the third contains 70%. He wants to use all three solutions to obtain a mixture of 40 liters containing 45%

acid, using 2 times as much of the 70% solution as the 25% solution. How many liters of each solution should be used?

How to set up as three linear equations to find the answer?

Follow2

Add comment

More

1 Expert Answer

By:

Best

Arthur D. answered • 06/28/17

TUTOR 4.9 (67)

Forty Year Educator: Classroom, Summer School, Substitute, Tutor

ABOUT THIS TUTOR ›

set up 2 equations

the first equation...

15%*x+25%*y+70%*2y=45%*40

0.15x+0.25y+1.4y=0.45*40

0.15x+1.65y=18

multiply all terms by 100

15x+165y=1800

divide all terms by 15

x+11y=120

the second equation...

x+y+2y=40

x+3y=40

x=40-3y

substitute into the first equation x+11y=120

40-3y+11y=120

40+8y=120

8y=120-40

8y=80

y=80/8

y=10 liters

x+3*10=40

x+30=40

x=40-30

x=10 liters

10 liters of 15%, 10 liters of 25%, and 20 liters of 70%

check:

10*15%=1.5

10*25%=2.5

20*70%=14

1.5+2.5+14=18

18/40=9/20=45/100=45%

45%*40=18

hope it helps

please mark brainliest

8 0
3 years ago
Which of the following is not the same as postive 7​
shusha [124]
Am I suppose to be looking at a picture?
8 0
2 years ago
len bought a new car for $22,500. after a few years he sold the car at a discount of 25% what are the selling price of the car?
Gala2k [10]

Answer:$16,875

Step-by-step explanation:

25% of 22500 is 5625.

22500-5625=16875.

4 0
2 years ago
Read 2 more answers
Other questions:
  • Please help!! I need to know this by today
    7·2 answers
  • Is 0.9 a real number
    6·2 answers
  • The height of a prism,cylinder, pyramid, or cone is always_ to the base
    10·1 answer
  • PLEASE HELP!!!<br> Calculate the length of segment with the midpoint.
    6·2 answers
  • What does -43 plus 17 equal?
    7·2 answers
  • 15,000 invested at a rate of 4.8% compounded monthly. Write a compound interest function to model the situation . Then find the
    7·2 answers
  • WILL MARK BRANLIEST IF GOTTEN RIGHT
    13·1 answer
  • If -7x+68=159 what is x
    7·1 answer
  • Find the value of x and each arc measure
    9·1 answer
  • Please help!<br> 5^3 x 5^-7
    9·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!