To write the expression in its simplest form, we need to simplify each term and then combine like terms.
The first term of the expression is 2x²y. This term is already in its simplest form and doesn't require any further simplification.
The second term of the expression is xy. This term is also in its simplest form and doesn't require any further simplification.
The third term of the expression is -3x. This term is also in its simplest form and doesn't require any further simplification.
The fourth term of the expression is 12x.xy. To simplify this term, we need to distribute the 12 over the x and y. So, we get 12x.y.
Now that all terms are simplified, we can combine like terms. Since the terms xy and 12x.y are the same, we can add them together to get (12+1)xy = 13xy.
So, the expression in its simplest form is 2x²y + 13xy - 3x.
We can further simplify the above expression by combining x²y and xy together as (x²+1)xy = x³y
So, the final expression in its simplest form is x³y + 13xy - 3x.