Factorise `12a^2 b + 15ab^2`

Explanation

To factorise the expression \( 12a^2b + 15ab^2 \), we can follow these steps:

### Step 1: Identify the common factors
We start by looking for common factors in both terms of the expression \( 12a^2b \) and \( 15ab^2 \).

### Step 2: Factor out the coefficients
The coefficients of the terms are 12 and 15. The greatest common divisor (GCD) of 12 and 15 is 3.

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