Question

Find the 12th term of the arithmetic sequence whose common difference is d = -7 and whose first term is a 1 = 30 .(Picture is more understandable)

Answer 1

T12 = -47

Explanations:

The nth term of an arithmetic sequence is expressed as:

`T_n=a+(n-1)\cdot d`

where:

• a is the, first term

,

• n is the ,number of terms

,

• d is the ,common difference

Given the following parameters

a = 30

n = 12 (12th term)

d = -7 (common difference)

Substitute the given parameters into the formula

`\begin{gathered} T_(12)=30+(12-1)\cdot(-7) \\ T_(12)=30+11(-7) \\ T_(12)=30-77 \\ T_(12)=-47 \end{gathered}`

Hence the 12th term of the arithmetic sequence is -47