Question

Find the first, fourth, and tenth terms of the arithmetic sequence described by the given rule.

–2.2, –11.8, –19.8

–3, –11.8, –25

–3, –9.6, –22.8

0, –6.6, –19.8

Answer 1

–3, –9.6, –22.8

Explanation:

Given rule is:

`A(n) =-3+(n-1)(-2.2)`

So,

For first term:

`A(1) =-3+(1-1)(-2.2)\\A(1) = -3 +0\\= 0`

For fourth term:

`A(4) =-3+(4-1)(-2.2)\\=-3+(3)(-2.2)\\=-3+ (-6.6)\\=-3-6.6\\= -9.6`

For tenth term:

`A(10) =-3+(10-1)(-2.2)\\=-3+(9)(-2.2)\\=-3+ (-19.8)\\=-3-19.8\\= -22.8`

The first, fourth and tenth terms are -3, -9.6 and -22.8 respectively.

So, third option is correct ..