Hello,
1155=3*5*7*11
3,5*7*11
5,3*7*11
7,3*5*11
11,3*5*7
3*5,7*11
3*7,5*11
3*11,5*7
7 cases:
1) p+q=5*7*11
p-q=3
==>p=(5*7*11+3)/2=194
==>q=(5*7*11-3)/2=191
194²-191²=1155 Solution 1.
2) p+q=3*7*11
p-q=5
==>p= 118
==>q= 113
118²-113²=1155 Solution 2.
3) p+q=3*5*11
p-q=7
==>p= 86
==>q= 79
86²-79²=1155 Solution 3.
4) p+q=3*5*7
p-q=11
==>p= 58
==>q= 47
58²-47²=1155 Solution 4.
5) p+q=7*11
p-q=3*5
==>p= 46
==>q= 31
46²-31²=1155 Solution 5.
6) p+q=5*11
p-q=3*7
==>p= 38
==>q= 17
38²-17²=1155 Solution 6.
7) p+q=5*7
p-q=3*11
==>p= 34
==>q= 1
34²-1²=1155