Two input nand gates and inverters to sum three products
Simplify \$A'C'D+AC'D'+AB' ==&gt; C'(A \oplus D)+AB' \$

You can draw \$(A \oplus D)\$using two-input NAND gates.

Let \$(A\oplus D)\$ = \$ X\$, 

i.e, the equation becomes:
$$C'X+AB' $$

Using De-Morgan's theorem, we can tweek the equation into:

$$\overline{\overline{(C'X)}.\overline{AB'}}$$

Now you can directly draw the circuit using NAND and NOT gates.