-40 +2n= 4n -8(n+8)
-40 +2n= 4n -8n -64
-40 + 2n = -4n -64
2n = -4n -64 +40
2n=-4n-24
2n+4n=-24
8n=-24
N= -3
Answer is n equals -3
1. If you have 1 first then... 1,2,3,4 - 1,3,2,4 - 1,2,4,3 - 1,3,4,2 - 1,4,3,2 - 1,4,2,3
2. If you have 2 first the.... 2,1,3,4,- 2,1,4,3 - 2,3,1,4 - 2,3,4,1 - 2,4,3,1- 2,4,1,3
3. And so one with 3,4
Hope this helps:)
-149 would be your answer