Answer:
![12x^5-6x^(2) -9x+12](https://img.qammunity.org/2021/formulas/mathematics/high-school/xe77lhw7b1ey8i5oyr7kdtxi181siqrdho.png)
Explanation:
To put a polynomial in standard form, you would need to write its terms in the order of highest to lowest degree. The degree is the exponent of a term's variable.
is the only equation out of all the choices that satisfies that requirement. (Remember that the degree of -9x is 1. A term with just one variable with no exponent written still has a degree of 1. Also, 12 is a constant, or a number with no variable, so it has a degree of 0.)