12x^3 + 5 + 5x^2 -6x^2 - 3x^3 -9 - x12x3+5+5x2−6x2−3x3−9−x
12x^3 - 3x^3 + 5x^2 - 6x^2 - x - 9 + 5, color(purple)(" rearranging like terms together and in the decreasing order of the exponant"12x3−3x3+5x2−6x2−x−9+5, rearranging like terms together and in the decreasing order of the exponant
9x^3 - x^2 - x - 4, color(purple)(" simplifying"9x3−x2−x−4, simplifying
color(green)("Degree of polynomial " - 3Degree of polynomial −3
color(green)("No. of terms " - 4No. of terms −4