I don't think this is possible...
But if you mean 9 then the root is 3
1)Y=165000(1-0.04)^t
2)y=165000(1-0.04)^20=?? Use the calculator
You are able to pay expensive dues forward, such as houses, cars, and other payments that you wouldn't be able to pay in full on the spot.
That would be : 6fg^3 + 5f^2g^2 + f^3g - 7....because there are no like terms