Linear systems word problem:

astrid is running a concession stand at a basketball game. she is selling hot dogs and sodas. each hot dog costs $1.50 and each soda costs $0.50. at the end of the night she made a total of $78.50. she sold a total of 87 hot dogs and sodas combined. she must report the number of hot dogs sold and the number of sodas sold. how many hot dogs were sold and how many sodas were sold?