Answer:
x=-6
Step-by-step explanation:
7x-9x=6+6
-2x=12
x=-6
let's recall the vertical line test, it's a function if when dropping a vertical line on the graph, it only touches it once on the way down.
Check the picture below.
Given:

To find the degree of the polynomial:
The degree of the given polynomial is, 2+3=5
So, the given polynomial is a fifth-degree polynomial.
Thus, the answer is a fifth-degree polynomial.