Answer:
n =7
Explanation:
(n+1) +1 + (n-1) = value first row
3+ (2n-9) +n = value second row
The value has to be the same
Set the equations equal
(n+1) +1 + (n-1) =3+ (2n-9) +n
Combine like terms
2n+1 = 3n-6
Subtract 2n from each side
2n+1-1 -2n = 3n-6-2n
1 = n-6
Add 6 to each side
1+6 = n-6+6
7 = n