Word problem
posted by Gene .
A new car worth 45K is depreciating in value by 5K per year. How can I write a formula that models the cars' value,y, in dollars, after x years?Then using the formula determine after how many years the cars' value will be 9K.

Substitute 4d for e in second equation and solve for d. Insert that value into the first equation and solve for e. Check by inserting both values into the second equation.