Consider x, y, z are three consecutive terms of a G.P. such that x + y + z = -120 and y = 80. Find xyz. ?
512000
Let r be the common ratio of the G.P.
80r + 80 + 80r = -120
Solving we get r = -2 or - (12)
So x and z will be -160 and -40 or -40 and -160 respectively.
xyz = 512000