posted by vinci on .
A house and a lot together cost more than $86,000. The house costs $2000 more than six times the costs of the lot. How much does the lot cost by itself?
If house costs x and lot costs y then x+y=86000, and x=6y+2000 or x-6y=2000.
Subtracting second eq. from first we get
6y+y=86000-2000 or 7y=84000 or y=12000.
Thus lot costs $12000
House costs 86000-12000=$74000.