Answer
This polynomial is a trinomial of the second degree.
Work Step by Step
We should rewrite this expression in order of descending powers to be able to see which term has the greatest power.
$$6x^2 + 9x - 4$$
First of all, we see that this polynomial has three terms, so we call it a trinomial.
To determine what degree the polynomial is, we examine the polynomial that we had rewritten and look at the first term. The first term is $6x^2$, and we look at the exponent on the $x$, which is a $2$; therefore, the polynomial is of the second degree.
So this polynomial is a trinomial of the second degree.