A new color copier purchased for $8.500 is
expected to depreciate (lose value) accord-
ing to the equation y=-1,250x+8,500,
where y is the value of the copier x years
after it was purchased. The company that
bought the copier plans to sell it when
the value is $1,000 and upgrade to a new
one. How many years after the copier is
purchased will the company sell it?