Simplify the expression by combining like terms

10ab+2ab2-9ab

The simplified expression by combining like terms is:

(10 + 2 - 9)ab^2 = 3ab^2

To simplify the expression by combining like terms, we need to add or subtract the terms that have the same variables and exponents.

In this case, we have the terms:
10ab, 2ab^2, and -9ab

Since all the terms have the same variables "a" and "b", we can combine them by adding or subtracting the coefficients.

Adding the coefficients:
10 + 2 - 9 = 3

The simplified expression is:
3ab + 2ab^2