any three consecutive terms a, b and c of geometric progression will satisfy the following equation:

b^2=ac

where b is considered to be the geometric mean between a and c.

in our case we have

(x + 2)^2 = x(x + b)

by solving for x we find:

x = 4/(b - 4)

click here to see the step by step solution of the equation:

x + 2 = 4/(b - 4) + 2 = (4 + 2b - 8)/(b - 4) = (2b - 4)/(b - 4) = 2(b - 2)/(b - 4)

x + b = 4/(b - 4) + b = (4 + b^2 - 4b)/(b - 4) = (b^2 - 4b + 4)/(b - 4) = (b - 2)^2/(b - 4)

the three terms of the geometric progression are: 4/(b - 4), 2(b - 2)/(b - 4) and (b - 2)^2/(b - 4).