Question

The eighth term of a linear sequence is 26. The term-to-term rule is 'add 3
Work out the fourth term of the sequence.
Explain the method you used to solve this problem.

Answer 1

• Common difference=d=3

Let a be first term

$\\ \rm\longmapsto a_8=a+7d$

$\\ \rm\longmapsto 26=a+7(3)$

$\\ \rm\longmapsto a=26-21$

$\\ \rm\longmapsto a=5$

Now

$\\ \rm\longmapsto a_4=a+3d$

$\\ \rm\longmapsto a_4=5+3(3)$

$\\ \rm\longmapsto a_4=5+9$

$\\ \rm\longmapsto a_4=14$