@billyshears.... You asked how to "solve for the sale equity" (last cash flow), not how to use the IRR function.

But your initial posting contains several contractions and ambiquities that make it difficult to offer a turnkey solution.

First you say that you want to sell "in

*year 4* [....] to achieve a

*9%* IRR".

Then you say that you set your "goal IRR in

*Year 3* to be

*10%*".

Which is it?

Also, you say that in Year 1 and 2, you "

*get* 9% on my money".

What do you mean by "get"? That is, from what source: rent?

With a $100 investment, did you receive $9 in each of Year 1 and Year 2?

Or do you mean that the property value appreciates to a value of $109 in Year 1 and $118.81 in Year 2 (9% compounded)?

Or do you mean something else entirely?

It would be much easier if you simply tell us what the cash flows are (dollar amounts) in Year 1 and 2.

And again, tell us what those cash flows represent (e.g. rent) so that we can be sure that the cash flow is appropriate.

Ostensibly, with the initial investment and Year 1 and 2 cash flows in A1:A3, the required Year 3 cash flow for a 10% IRR is (in A4):

=-SUMPRODUCT(A1:A3/(1+10%)^{0;1;2})*(1+10%)^3

Confirm that =NPV(IRR(A1:A4),A1:A4) is zero or nearly so.

Caveat: You might use different separators for parameters and array constants. Be sure to use the

*row* separator for the array constant {0;1;2}.