What do we call our system of numeration

Aflute is on sale for 20% off. including the discount and 8% tax, the sales price is $216.

The price for gasoline is represented by the equation y=3.69x, where y represents the total price for x gallons of gasoline. on a graph, the number of gallons is represented on the horizontal axis, and the total price is represented on the vertical axis. determine whether each statement describes the graph of the equation. select true or false for each statement

Find an equation of variation where y varies directly as x and y 75 when x5, findy when x is 1