Question about Filters in Image Processing

I have three question about this matrix.

I tried to solve for question 6 and 7. But i'm not sure.

I don't have an idea about Question 8.

I tried this code for solving.

A=[14 12 10 12 11 10 13 7 9 16;

16 14 13 13 12 6 9 10 13 11;

16 14 12 13 11 8 9 11 11 3;

13 13 12 12 15 11 12 12 4 3,

16 9 4 12 14 8 9 21 11 5;

16 15 15 12 8 8 5 5 6 12;

12 11 13 11 13 4 4 3 2 5;

7 7 13 13 14 4 4 3 4 5;

8 11 5 12 12 4 5 4 4 5;

14 14 12 6 12 5 2 3 5 3]

......................................................................Question 6

T=medfilt2(A,[3 3]);

T

..................................................................Question 7

A=uint8(A);

H=fspecial('average',[3 3]);

T=imfilter(A,H);

T

.......................................................... Question 8 (it is not working)

A=uint8(A);

H = fspecial('laplacian',0,2)

T=imfilter(A,H);

T

If you help me, i will be very happy.