$3 subtracted from the cost of the book

a function could be identified in 3 ways either on a chart,graph, or ordered pairs. first a function is that each point has its own. the rule is that there can be many x's to one y but there can not be 2 x's at different y's. so on a graph when you put a straight line through the y's there should be one dot only to be a function.

step-by-step explanation:

x= cost per bracelet

number of bracelets * x + shipping charge = total cost

so

9x+9=72