You just need to try with all of the pair f.ex 0,-2 -> put 0 in the x-> y=8*0-2=-2 so ok it is q possible pair of the function.. You try every pair till you find set where all the pairs fit So set 1 1 and 6: 8*1-2=6 ok 2 and 14 : 8*2-2=14 ok Hope I could help
