Convolutions:

original: [ 5 5 5 9 9 9 8 7 6 5 -5 0 0 0 0 ]

using filter [ -1 1 ] : [0 0 -4 0 0 1 1 1 1 10 -5 0 0 0]

using filter [ 1 -1 ] : [0 0 4 0 0 -1 -1 -1 -1 -10 5 0 0 0]

using filter [ 1 0 0 1 ] : [14 14 14 17 16 15 13 2 6 5 -5 0]

using filter [ 1 0 0 -1 ] : [4 4 4 -1 -2 -3 -3 -12 -6 -5 5 0]

Last question: