The sequence 6,-9,x,y is such that the first three terms form an arithmetic sequence and the last three terms form a geometric sequence. Find x and y. Express your answer as x,y
The common difference is second term - first term = - 9 - 6 = - 15
So the third term is -9 - 15 = -24
And the common ratio is third term / second term = -24 /-9 = 8/3
So....the fourth term is -24 (8/3) = -64
So x , y = -24, -64
