Gavin works as a salesperson at an electronics store and sells phones and phone

Gavin works as a salesperson at an electronics store and sells phones and phone accessorries. Gavin earns a 12$ commission for every phone he sells and a 3.50 commision for every accessory he sells. On a given day, Gavin made a total of $135 in commission and sold 12 more accessories than phones. Determine the number of phones sold and the number of accessories sold.