A car repair shop charges $1 for mounting a tire purchased from the shop. The repair shop charges $7 for mounting a tire that was purchased from another shop. Last month, the total charges for mounting tires were $776. The number of tires mounted and purchased from the shop was 424 less 3 times the number of tires mounted that were purchased from other shops. Write and solve a system of equations to find the number of tires purchased from the shop and from other shops
The shop mounted__tires purchased from the shop and__tires purchased from other shops