Question

Module 9 Concept Questions Version 3.0 August 2019 Concept Questions for Module 9 Your Name: Instructor's Name: 1) [9.5] Applications to interest: interpreting unusual answers. Mike plans to invest money in two savings accounts. One earns 5% annual interest and the other earns 7% annual interest. He plans to invest a total of $4000 in the two accounts, and wants to earn total interest of $320. How much would he need to invest in each account? a) Clearly define two variables to stand for the unknown quantities. b) Write a system of two equations in two unknowns representing the situation. c) Solve your system. Use any method of your choice, but indicate how you solved it. (You should get a strange solution. That's OK.) d) Using your answer to (c), explain to Mike why what he wants is not possible. 2) [9.6] Applying a system of three equations. A change purse contains $5.75 in nickels, dimes, and quarters. There are a total of 48 coins in the purse, and the number of nickels is 5 more than the number of quarters. How many of each type of coin are in the purse? a) Clearly define 3 variables to stand for the unknown quantities. b) Write a system of 3 equations in 3 unknowns representing the situation. c) Solve your system. Use any method of your choice, but indicate how you solved it. d) How many of each type of coin are in the purse?