Step-by-step explanation:

Answer:
To know if it is a function see if there are two of the same x-intercept( which makes a vertical line). If there is,then it is not a function.
Answer:
$5.23
Step-by-step explanation:
(7x.25)+13(.05)+.23+6(.10)+2.00=1.75+.65+.23+.60+2.00=$5.23