107 can be answer
If we take 1st digit of next line and multiply with 1st digit of starting line and substract 1st digit of starting line numbers.and if we notice one row is odd and other is even but the question line is opposite of above line.
Eg. 3 2
5 4
7 6
9 8 so next should be
11 10 but in question i.e. 10 9 so we can find answer this way. 4 3
7 6
10 9
13 12
eg. 5*2-3=7
7*4-5=23
9*6-7=47
11*8-9=79
13*9-10=107