Question

@hartnn

Answer 1

since the sequence is arithmetic, the difference between consecutive terms are equal

so, x - 2.2 = 6 - x
find x from here

Answer 2

2x=8.2x=4.1

Answer 3

correct!

Answer 4

When terms are in geometric sequence, the ratio between the consecutive terms is constant

so,
6/x = x/54

Answer 5

or in other words, if b is the geometric mean of a and c
then \(b^2 = ac\)

Answer 6

So b^2=6*54
b^2=324
sqrt b^2 = sqrt 324
b=18

Answer 7

18 is also correct :)

Answer 8

Okay great!

Answer 9

but incomplete

Answer 10

\(b^2 = 18^2 \\ b = \pm 18\)
don't forget the negative root too!

Answer 11

Yeah I know!