Question

Find a common difference of the arithmetic sequence -2, -1 4/5, -1 3/5, -1 2/5,

Answer 1

The common difference is
`(1)/(5)` or 0.2

Explanation:

Given:

Arithmetic Sequence -2, -1 4/5, -1 3/5, -1 2/5,

First term = a₁ = -2

Second term = a₂ =
`(-9)/(5)`

Third term = a₃ =
`(-8)/(5)`

Fourth term = a₄ =
`(-7)/(5)`

To Find:

Common Difference = d = ?

Solution:

Formula for Common Difference d ,
`\textrm{common difference}= \textrm{Second Term} -\textrm{First Term}=\textrm{Third Term}-\textrm{Second Term}`

`\textrm{common difference} = a_(2)- a_(1)= a_(3)- a_(2)=a_(4)- a_(3)`

∴
`d = (-9)/(5)-(-2)\\d=(-9)/(5)+2\\d=(1)/(5)\\ \therefore d =0.2\\`

The common difference is
`(1)/(5)` or 0.2