Please Help!! Urgent

Question

Three houses were for rent by the Jippem Realty Company. They charged $300 more per month for the second house than for the first. The third house rented for the same as the second, but was vacant for 2 months for repairs. How much per month did each house rent for if the rent receipts for the year were $37200?

Answer 1

house rent for house 1 = x

house rent for house 2 = y

house rent for house 3 = z

y = x+300

z =y

amount received from house 1 = 12x

amount received from house 2 = 12y = 12(x+300)

amount received from house 3 = 10 z = 10 y =10(x+300)

12x + 12(x+300) + 10(x+300) =37200

12x+ 12x +3600 +10x +3000 = 37200

34x +6600 = 37200

34x = 30600

x = 900

y = 900 +300=1200

z=1200

house rent for house 1 = x= $900

house rent for house 2 = y=$1200

house rent for house 3 = z= $1200