Final answer:
To determine the dollar amount of phone sales and computer sales Anna made, we can write a system of equations. The first equation represents the commission earned on phone and computer sales, while the second equation represents the total sales made. Solve this system to find the values of x and y.
Step-by-step explanation:
Let x represent the dollar amount of phone sales Anna made and let y represent the dollar amount of computer sales she made. We can use the following system of equations to determine the values of x and y:
Equation 1: x + y = 2100 (Total sales equation)
Equation 2: 0.05x + 0.07y = 119 (Commission equation)
Equation 1 represents the fact that the total dollar amount of phone sales (x) plus the total dollar amount of computer sales (y) equals the total sales made ($2100).
Equation 2 represents the fact that Anna earned a 5% commission on all phone sales (0.05x) and a 7% commission on all computer sales (0.07y), and the total commission earned ($119).