1 Write down all the possible factors for each of the following expressions. 1.2 Determine the H.C.F. of the algebraic expression 3a2b + 4ab2.

• For $3a^2b$: The factors are the combinations of the numerical factors of 3 ($1, 3$) and the variable factors of $a^2b$ ($1, a, a^2, b, ab, a^2b$). Factors: $\boxed{1, 3, a, a^2, b, ab, a^2b, 3a, 3a^2, 3b, 3ab, 3a^2b}$

• For $4ab^2$: The factors are the combinations of the numerical factors of 4 ($1, 2, 4$) and the variable factors of $ab^2$ ($1, a, b, b^2, ab, ab^2$). Factors: $\boxed{1, 2, 4, a, b, b^2, ab, ab^2, 2a, 2b, 2b^2, 2ab, 2ab^2, 4a, 4b, 4b^2, 4ab, 4ab^2}$

The algebraic expression is $3a^2b + 4ab^2$. We need to find the H.C.F. of the terms $3a^2b$ and $4ab^2$.