1+4=5 2+5=12 3+6=21 8+11=? puzzle answer

i came up with 97

1+4=5
2+5=12
(7+5=12)
3+6=21
(9+12=21)
4+7=33
(11+21=33)
5+8=46
(13+33=46)
6+9=61
(15+46=61)
7+10=78
(17+61=78)
8+11=97
(19+78=97)

The answer is 97. The first expression is 1+4=5. In the next expression, both numbers are increased by 1 while their sum is increased by 7: (1+1)+(4+1) = (5+7). 2+5=12. In the next expression, both numbers are increased by 1 again, but the sum is increased by the next odd number (which is 9): (2+1)+(5+1)=(12+9). 3+6=21. So, the series will look like this: 1+4=5. 2+5=12. 3+6=21.4+7=33. 5+8=46. 6+9=61. 7+10=78- 8+11=97.

What class is this? i have no idea and i'm not going to give you the wrong answer. do you have a graph that goes with all the questions