Question

-8, -11, -14, -17, -20, ...

Find the 30th term of this Arithmetic Sequence.

Answer 1

Explanation:

arithmetic sequence means that every new term is created by adding a certain constant to the previous term.

clearly, we see here, this constant is -3.

and we start with -8.

a1 = -8

a2 = a1 - 3 = -8 - 3 = -11

a3 = a2 - 3 = a1 - 2×3 = -8 - 6 = -14

so, it becomes clear that

an = an-1 - 3 = a1 - (n-1)×3 = -8 - (n-1)×3

so,

a30 = -8 - 29×3 = -95

Answer 2

-95

Explanation:

formula in finding this is -3

Arithmetic Sequnce:

-8, -11, -14 ,-17,-20,-23,-26,-29,-32,-35,-38,-41,-44,-47,-50,-53,-56,-59,-62,-65,-68,-71,-74,-77,-80,-83,-86,-89,-92,-95.

Carry on learning