It is a fact that the earth appears to be about 4.5 billion years old.
That is based on the best science as we currently understand it.
The best science has been dead wrong at times, but is also often correct.
God may very well have created the eart in a mature state ready to support life at once, this would result in an earth that appears to be much older than it in fact is.
God may also have created the universe 13 billion years ago, waited 8.5 billion years, created the earth, waited 4.5 billion years, then created man.
There are a number of indicators that suggest an old universe and old earth, something on the order of the 4.5 billion year old model. There are some that suggest an age of several thousand years. The science on this issue seems to point in a certain direction, but is not settled.
The Bible seems to suggest a younger rather than older date of creation, but there is at least some room left for an older earth.
I suspect that the truth is somewhere between 6,000 years and 4.5 billion years, but I am not sure just where.