Hopefully I am factoring...
1st take the 2 out of the expression
[tex]2(n^2+7n-8)[/tex]
Look at the 2nd sign, since it is negative the signs in the factors will be +/-. Now we need the numbers that multilpy to 8 and have a difference of 7, which will be 8 and 1.
[tex]2(n+8)(n-1)[/tex] - factored form