Math Problem Statement

The start of an arithmetic sequence is shown below. Work out the two missing terms in the sequence: _, 10, _, 28, ...

Solution

The sequence provided is an arithmetic sequence, where the difference between consecutive terms is constant. You are given the terms:

_,10,_,28,\_, 10, \_, 28, \dots

Let the common difference be dd. Using this, we can set up the following relationships based on the definition of an arithmetic sequence:

  • The second term is 10: a+d=10a + d = 10

  • The fourth term is 28: a+3d=28a + 3d = 28

Now, subtract the first equation from the second: (a+3d)(a+d)=2810(a + 3d) - (a + d) = 28 - 10 2d=182d = 18 d=9d = 9

Now, substitute d=9d = 9 back into the first equation to find aa: a+9=10a + 9 = 10 a=1a = 1

So the first term is 1, and the common difference is 9. Using this, we can now find the third term: 1+2(9)=1+18=191 + 2(9) = 1 + 18 = 19

Thus, the sequence is:

1,10,19,28,1, 10, 19, 28, \dots

The two missing terms are 1 and 19.

Would you like more details or have any questions? Here are five related questions you could explore:

  1. How do you find the sum of the first nn terms of an arithmetic sequence?
  2. What is the formula for the general term of an arithmetic sequence?
  3. Can you explain the difference between arithmetic and geometric sequences?
  4. How would the sequence change if the common difference were negative?
  5. How can arithmetic sequences be applied in real-world problems?

Tip: Always double-check the common difference when working with arithmetic sequences to avoid mistakes in identifying missing terms.

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Math Problem Analysis

Mathematical Concepts

Arithmetic Sequences
Algebra

Formulas

General term of an arithmetic sequence: a + (n-1)d

Theorems

Definition of an arithmetic sequence

Suitable Grade Level

Grades 7-9