Question

Find the first term of the following geometric sequence:

, 42, 126, 378, 1,134, ...

A. 16
B. 18
C. 14
D. 21

Answer 1

is a geometric sequence
thus to get the "next" term, you'd multiply the "current" term by some value

now, if you divide the "next" term by the "previous" or "current" term, you'd get the
common ratio, or the value that's being used to multiply and get the next term

so the number before 42, was "something"
and "something" * that value or common ratio" = 42

Answer 2

so... find the common ratio
divide 42 by that, and that'd be the term before it

Answer 3

14 @jdoe0001