An electronics store sold a total of $1,500 worth of televisions and sound systems. All televisions were sold at a 20% markdown from their original price, and all sound systems were sold at a 10% markdown from their original price. If the total original price of the items sold was $1,800, which system of equations can be used to find the original price, in dollars, of the televisions, , and the original price, in dollars, of the sound systems, ?
