How to Find the X of a Geometric Sequence

By Stefan Robert

Finding the X of a geometric sequence will involve using a few other numbers that you will already know. Find the X of a geometric sequence with help from an expert in computers, with two degrees in both Computer Science and Applied Mathematics, in this free video clip.


Hi, my name is Stefan. Today, I'm going to be speaking on how to find the X of the unknown in a geometric sequence. Now say for example we have the sequence 2X and 4X and 24. Well we know that in the geometric sequence we're always multiplying by the same thing, by the same constant to get the next number. So we divide 4X by 2X, this cancels and this gives us 2. So we multiply by 2 to get the next number here. So 4X x 2 = 24. So that's X = 3 and when you plug it in, we get our original numbers, 2 x X which is 3 so that gives us 6 and 4 x X which is 3 which gives us 12 and 24 and then we have our geometric sequence.