The answer is -4.3!!!!!!!
X=11, set 10x+5x+15=180
15x+15=180, subtract 15 from 180= 165, then divide 165 by 15
To answer the question, simplify the polynomial by adding those that has the same degree of variable,
6 - 3x + (6x³ - 2x³)
6 - 3x + 4x³
Rearrange the polynomial with decreasing exponent or x,
4x³ - 3x + 6
This is a third-degree polynomial.