The meaning of this equation is that the rate of change of the number of nuclei over time is proportional only to the number of nuclei.
This is consistent with the assumption that each decay event is independent and its chance does not vary over time.
This leaves out important information which would tell you how precise is the dating result.
Carbon-14 dating has an interesting limitation in that the ratio of regular carbon to carbon-14 in the air is not constant and therefore any date must be calibrated using dendrochronology.
Carbon-14 decays almost completely within 100,000 years of the organism dying, and many fossils and rock strata are hundreds of times older than that.
To date older fossils, other methods are used, such as potassium-argon or argon-argon dating.
Segment from A Science Odyssey: "Origins."Geologists have calculated the age of Earth at 4.6 billion years.Scientists discovered that rocks could be timepieces -- literally.