let x = the number of sq feet of storage space
5x = the number of sq feet of showroom space
5x(1.15) + x(0.50) = 1500
575x + 50x = 150,000
625x = 150,000
x = 240 square feet (the amount of storage space)
5 * 240 = 1200 square feet (the amount of showroom space)