How can you write the expression with a ratio with a rationalized denominator 2+sqrt5/2-sqrt5

Issof claims that the scale factor is 1/2. which statement about his claim is correct

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.

The table represents a function f(x). what is f(3)? a.-9 b.-1 c.1 d.9