Answer is 125

Answer is 10

How?
There is gap of 4 between numbers
8+4 = 12
3+4 = 7
9-5 = 4
simillarly
?-4 = 6=> ?=10

NOTE: there is a better and shorter explanation(suggested by Guestlogic in comment), opposite numbers sum is 15, that’s why answer should be 15 – 5 = 10

Answer courtesy Sandy, in disqus comments

Logic: For every row First column*2 + Second Column*3 = Third Column

for second row 9*2 + 17*3 = 69

for third row 13*2 + 11*3 = 59

for first row, lets say first column value is x, thus

x*2 + 13*3 = 49

2x = 49 – 39 = 10

x = 5