Please urgent help simple maths problem

[matthewcre]

This is for a finance course i am currently taking.

how do i find out what Y is in:

1 / (1+Y) + 1 / (1+y)^2 = 1.8

Any help would be greatly appreciated.

[Rassis]

Sequentially, you do the following:

1+Y+1 = 1.8*(1+Y)^2
2 + Y = 1.8 + 1.8Y^2 + 3.6Y
Y^2 + 2.6/1.8Y - 0.2/1.8 = 0
Y = {-2.6/1.8 +/- sqrt[(2.6/1.8)^2 + 4*1*0.2/1.8]}/(2*1) = 0.073

If you prefer EXCEL, you have an easier way to get the result by using GOAL-SEEK in 6 steps:

1. In any one cell you estimate the result, enter 2 for instance;
2. In any other cell you compute your equation making Y = 2 (the cell reference);
3. Then select Tools and Goal-Seek;
4. Set cell: Click on the cell showing your equation result;
5. To value: Enter 1.8;
6. By changing cell: Click on the cell where you wrote 2.

And the result is 0.073264

Rui