6 is a solution.
Work Step by Step
To determine which of the numbers in the set [10,6,8] solves the equation, isolate the variable. $5n+4=34$ Subtract 4 from each side. $5n=30$ We already know the number has to be a factor of 30, so you can eliminate 8 at this point. Now divide both sides by 5. $n=6$ Bingo!