Joanna has a total of 7 rolls of coins worth $23. She has rolls of dimes worth $5 each, and rolls of nickels worth $2 each.
How many rolls of each kind does she have?

The cost varies directly with the number of tickets purchased. it costs $145 for 10 people to attend a concert. a. what is the constant of proportionality (k)? b. write the direct variation equation. c. home much does it cost for 8 people? d. graph this situation. be sure to label each axis and give the graph a title.