Choose the expression that represents a cubic expression.

a. 19x^4 + 18x^3 - 16x^2 - 12x + 1

b. 10x^3 - 6x^2 - 9x + 12

c. - 9x^2 - 3x + 4

d. 4x + 3

b. 10x^3 - 6x^2 - 9x + 12

Step-by-step explanation:

A cubic expression has the highest power of the variable to the third power

x^3

b. 10x^3 - 6x^2 - 9x + 12

is the only expression that has the highest power as x^3

a has x^4 and c and d do not have an x^3 term