(I NEED THE ANSWER'S ASAP) Determine whether each statement is true or false.
(a) If 3 and 5 are factors of a number, then 15 is a factor of the number.
(b) If 246 is a multiple of a number, then 123 is a multiple of the number.

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.