Answer:
jack wants to paint his house. he collected quotes from two different painters. The first one total cost in terms of number of hours, (x), worked was modelled as (x) =70 +-5x whiel that of the second was (x)=40+10x jack knows that it wil take about 6 hours to paint the house.
Figured out that the cost quoted by the 2 paint are equal for 6 hours of work
