Question

Give an arithmetic sequence of 20,16,12find it’s common difference and the 25th term

Answer 1

Answer: Common difference = -4, and 25th term = -56

Explanation:

The common difference, d, is 20 - 16 or 16 - 12, which is -4.

Using the formula
`a_(n)=a_(1)+(n-1)d`,
`a_(25)=20+(20-1)*-4`

= 20 + 19 * -4,

= 20 - 76

= -56