David has a construction company that built 8 houses last year. Six of the houses required landscaping, which cost $8000 more per house.
Three of the houses had garages that cost an extra $7000 per house.
. Ben paid $15,000 more for his house than David's usual price.
. Marina paid the usual price for her house.
• The usual price for David's houses is the same without landscaping or a
garage.
No houses were completed in January.
Use the axioms to make three conclusions about the houses David built.