Which monomials are factors of -21a^2?

True or false? a triangle can be circumscribed about a given circle

Which choice represents the sample space ,s for this event

Steve wants to develop a way to find the total cost of any item including sales tax. the sales tax in his city is 6%. his friend jenna writes the expression x + 6x where x is the cost of the item. explain whether her expression is correct based on the situation.