Set up appropriate systems of two linear equations in two unknowns and then solve the systems by determinants. All numbers are accurate to at least two significant digits.

A new development has 3-bedroom homes and 4-bedroom homes. The developer’s profit was $25,000 from each 3-br home, and $35,000 from each 4-br home, totaling $6,800,000. Total annual property taxes are $560,000, with $2000 from each 3-br home and $3000 from each 4-br home. How many of each were built