Is this a correct way to use the equals sign?

14 × 2 = 28 + 2 = 30

You are correct, but this equation is not! "=" means that the expression on the left has the same value as the expression on the right, which isn't true for the = sign on the left:

Sometimes I call this a run-on equation.  In writing, you have to be careful to put your ideas together in a grammatical way, or you'll have a run-on sentence.  In math, you have to put your numbers together in a balanced way that keeps amounts the same or you'll have a run-on equation.