Find the correct result

1+4 = 5

2+5 = 12

3+6 = 21

5+8 =

Answer: 45

Step-by-step explanation:

As we can see here, the relation is as follows:

(1) (4) + 1 = 4+1 = 5

(2) (5) + 2 = 10+2 = 12

(3) (6) + 3 = 18+3 = 21

Then, if we follow the same pattern:

(4) (7) + 4 = 28+4 = 32

Hence:

(5) (8) + 5 = 40+5=45