Write System of Equations from Context Charlotte works at an electronics store as a salesperson. Charlotte earns a 10% commission on the total dollar amount of all phone sales she makes, and earns a 4% commission on all computer sales. Charlotte had twice as much in computer sales as she had in phone sales and earned a total of $162 in commission. Write a system of equations that could be used to determine the dollar amount of phone sales Charlotte made and the dollar amount of computer sales she made. Define the variables that you use to write the system.