Implementing Boolean Function F with NOR Gates

[ahmed-mii]

Homework Statement

1. Implement the following Boolean function F using no more than two NOR gates and draw the circuit.F(A,B,C,D)=∑(0,1,2,9,11)+d(8,10,14,15)
2. Implement the following Boolean function using two - level forms:
NAND - AND
OR - NAND and

Homework Equations

The Attempt at a Solution

The first one is kinda easy but I didn't what's the meaning of d.
The second one I'm actually Confused about the solution .First one is I draw NAND then AND
is this correct.

 

[ineedmunchies]

The d means does not matter. So that values of 8, 10, 14 and 15 can be either 1 or 0, whichever gives the neatest solution. I'm unsure about the second part, sorry.

 

[ahmed-mii]

Thank you for replying .Now,I know 'd' what's mean it's don't care .