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
Oksana_A [137]
3 years ago
8

If the fifth and eighth terms of an arithmetic sequence are minus 9 and minus 21, respectively, what are the first four terms of

the sequence?
Mathematics
1 answer:
Reil [10]3 years ago
4 0
One way to do this problem is to determine the common difference.  If the 5th and 8th terms are -9 and -21, we can do this by subtracting -9 from -21:

-21-(-9) = -12.  The 5th and 8th terms are not consecutive, so we have to think in terms of (8-5), or 3, times the common difference to get from -9 to -21.

Note that -12 divided by 3 is -4.  Thus, the common difference is -4.

Check:  -9 - 4 = -13; -13 - 4 = -17; -17 - 4 = -21 (which is correct).

We know that the 5th term is -9.  To find the 4th term, work backwards:  subtract (-4) from -9, which produces -9+4=-5.

The fourth term is -5.  Subtracting -4 from this (which is the same as adding 4 to this -5) produces the third term; it is -1.  Can you now find the 2nd and 1st terms using the same approach?

You might be interested in
Melissa is helping her dad build a walkway in their backyard. The walkway will be 545454 feet long and 1.51.51, point, 5 feet wi
sergiy2304 [10]

For the answer to the question above asking <span>Melissa is helping her dad build a walkway in their backyard. The walkway will be 545454 feet long and 1.51.51, point, 5 feet wide. The local hardware store sells tiles which are 1.51.51, point, 5 by 1.51.51, point, 5 feet and come in boxes of 121212.</span>
54 dived by 1.5 is 36.
36 dived by 12 is 3.
You need 3 boxes.
5 0
3 years ago
Read 2 more answers
Please help me with NUMBER 7 !! Thank you so much! 20 points!! :))
mart [117]

Answer:

x<-3 or x>-1

Step by step explanation:

Start with -5x>15. To get x by itself, we have to divide each side by -5. When we do that we get x<-3. (Don't forget to flip the sign when dealing with negative  · and ÷.) Now answer the second equation. x-5>-6 To get x by itself, add 5 to both sides to get x>-1. Now we have x<3 or x>-1.

8 0
3 years ago
The length of a rectangle is 6 units and its width is 4 units. What is the approximate length of the diagonal of the rectangle?
ss7ja [257]
The correct answer is:  [D]:  " 7.2 units" .
_______________________________________________________
Explanation:
________________________________________________________
Use the Pythagorean theorem:

a² + b² = c² ;

in which:  "6 units" and "4 units" equal the lengths of the right angle (formed by the rectangle);  and "c" is the length of the diagonal of the rectangle, or the "hypotenuse", of the right triangle formed by the rectangle;  We wish to solve for "c" ;
_______________________________________________

6² + 4² = c² ;  Solve for "c" ;

↔ c² = 6² + 4² ; 

         = (6*6) + (4*4) ;
 
         = 36 + 16 ;

        =  52 ;

    c² = 52 ;

Take the "positive square root" of each side of the equation; to isolate "c" on one side of the equation; and to solve for "c" ; 

  √(c²)  =  √52 ; 

    c = √52 ;  

At this point, we know the 7² = 49 ;  8² = 64 ;  so, the answer is somewhere between "7" and "8" ; yet closer to "7" ;  so among the answer choices given; 

The correct answer is:  [D]:  " 7.2 units" .
_________________________________________
However, let use a calculator:

c = √52 = 7.2111025509279786 ; which rounds to "7.2" ;
   which corresponds to:  
___________________________________________
Answer choice:  [C]:  " 7.2 units" .
___________________________________________
5 0
3 years ago
HELP HELP HELP First to HELP gets the brainliest :D
jasenka [17]

Answer:

 y= -\frac{1}{3}x -6

Step-by-step explanation:

Using the slope formula, you can form this equation! The slope of any equation would replace the m, and the y intercept would replace b!

I added in the slope formula at the bottom, just in case, so you'll see what I mean!

I hope this helps, and I explained enough! Have a great day c:

7 0
3 years ago
Read 2 more answers
Question shown in images
Mars2501 [29]
Answer is 2 (answer choice a)
5 0
3 years ago
Read 2 more answers
Other questions:
  • Which of the following Office Online apps is most effective for writing letters?
    7·2 answers
  • a system of equations has infinitely many solutions. if 2y – 4x = 6 is one of the equations, which could be the other equation?
    13·2 answers
  • For an intramural sports program at a particular college, the time to run one mile is recorded for 200 male students in the prog
    15·1 answer
  • Solve for x. Show work plz
    9·2 answers
  • PLS HELP I WILL DO ANYTHING!!!!
    6·1 answer
  • Find X and Y <br> I need help plz ASAP
    13·1 answer
  • How can I get equation x+4=-12 from equation x/4+1=-3
    10·1 answer
  • How many pounds of turkey?
    10·1 answer
  • Troy and Lisa were shopping for school supplies. Troy bought 3 notebooks and 5 thumb drives for $20.25. Lisa bought 8 notebooks
    8·1 answer
  • 4.Samuel used 1/5 of an ounce of butter to make 1/25 of a pound of jelly. How many ounces of butter is there per pound of jelly?
    12·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!