Question 92856
This is same as the equation of a straight line passing through (0, 900) and (5, 50).


So the equation is:
{{{(y - 50)/(900 - 50) = (x - 5)/(0 - 5)}}}
{{{(y - 50)/850 = -(x - 5)/5}}}
{{{y - 50 = -170(x - 5)}}}
{{{y = -170x + 850 + 50}}}
{{{y = -170x + 900}}}


Here x = time in years and y = cost in $.