In the expression x^2+4x^2+16x^2,x^2,4x^4, and 16x^2 are examples of _____

variables.

coefficients.

operations.

like terms.

Solve: 13x-4-9x+20=0

A.-12/11

b.6

c.-4

d.-6

A salesperson earns a salary of $800 per month plus 2% of the sales. Which inequality represents the total sales if the salesperson is to have a monthly income of at least $1600?