Mackenzie works as a salesperson at an electronics store and sells phones and phone accessories. Mackenzie earns a $10 commissio

n for every phone she sells and a $4 commission for every accessory she sells. On a given day, Mackenzie made a total of $126 in commission and sold 7 more accessories than phones. Write a system of equations that could be used to determine the number of phones sold and the number of accessories sold. Define the variables that you use to write the system.