43.2k views
5 votes
The sum of four consecutive odd integers is –72. Write an equation to model this situation, and find the values of the four integers.

1 Answer

4 votes

9514 1404 393

Answer:

  • (x -3) +(x -1) +(x +1) +(x +3) = -72
  • -21, -19, -17, -15

Explanation:

Let x represent the even integer between the middle two odd integers. Then the sum of the four odd integers is ...

(x -3) +(x -1) +(x +1) +(x +3) = -72

4x = -72

x = -18

The four integers are -21, -19, -17, -15.

_____

Additional comment

You could let x represent one of the integers. Often, people choose to let it represent the least of them. Then the equation becomes x +(x+2) +(x+4) +(x+6) = -72, so 4x = -84 and x = -21. This introduces a "subtract 12" step in the solution process that is unnecessary if x is chosen to be the average of the integers.

As the average, x is the sum divided by the number of them, so you know x=-72/4 = -18 immediately. Then you just have to find the nearest two odd integers below and above -18. You can do the whole problem mentally.

User Marcote
by
7.9k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories