Arithmetic Sequences and Their Terms

The video tutorial explains how to find the 20th term of an arithmetic sequence with a first term of -25 and a common difference of 7. It begins by introducing the problem and then derives the formula for the nth term of an arithmetic sequence. The formula is simplified by distributing and combining like terms. Finally, the tutorial demonstrates how to use the formula to calculate the 20th term, which is found to be 108. The video concludes with a brief summary of the solution process.

What is the first term of the sequence described in the video?

• 20

• 7

• 32

• -25

What is the common difference in the arithmetic sequence discussed?

• 32

• -25

• 7

• 20

Which formula is used to find the nth term of an arithmetic sequence?

• A sub n = A sub 1 / D

• A sub n = A sub 1 * D

• A sub n = A sub 1 + (n - 1)D

• A sub n = A sub 1 - D

After substituting the known values, what is the expression for A sub n?

• A sub n = -25 - 7n

• A sub n = 25 + 7n

• A sub n = -25 + 7n

• A sub n = 25 - 7n

What is the simplified expression for A sub n after combining like terms?

• A sub n = 32 - 7n

• A sub n = -32 + 7n

• A sub n = -32 - 7n

• A sub n = 32 + 7n

How do you calculate the 20th term using the simplified formula?

• Substitute n = 20 into A sub n = 32 + 7n

• Substitute n = 20 into A sub n = -25 + 7n

• Substitute n = 20 into A sub n = -32 + 7n

• Substitute n = 20 into A sub n = 25 + 7n

What is the value of the 20th term in the sequence?

• 108

• 140

• 32

• 25