600 divided by 20=30
30x2=60 which is the answer
equation= 600=2x area divied by height
To get -2 from 2, you would multiple by -1.
To get 2 from -2, you also would multiple by -1.
Ad infinitum.
So the common ratio is -1.
Hope this helps.
Because there is no solution if any number divide by 0