15ab2 + 2ab2x + 3ab2 + 2ab2x + 2ab2 = _____
20ab2 + 4ab2x
15ab2 + 2ab2x + 3ab2 + 2ab2x + 2ab2
= (15ab2 + 3ab2 + 2ab2) + (2ab2x + 2ab2x)
= (15+3+2)ab2 + (2+2)ab2x
= 20ab2 + 4ab2x
This cannot be simplified further as 20ab2 and 4ab2x are unlike terms.