Answer:

To generalise means to make a statement which holds in all cases, not just in some particular cases. A generalization is often expressed algebraically.

For example,



The diagram shows that the 4th triangle number is (4 x 5) / 2 (because two lots of the 4th triangle number make a 4 by 5 rectangle). The method can be generalized as : the n th triangle n(n + 1) / 2.