As Grigori noted in his description, the answer is 1. I believe it is easier to see in the following.
5/7n-3/14+14/3=1/2+14/3
Since we have + 14/3 on both sides we can cancel those out by subtracting it from each side, which leaves.
5/7n-3/14=1/2
Then we move the leave the variable (n) on the left and move the number to the right side of the equation by adding 3/14 to each side we get
5/7n=1/2+3/14 --> 5/7n=10/14 --> 5/7n=5/7
Which can now be seen to be solvable by multiplying each side by 7/5
7/5*5/7n = 7/5*5/7 --> 1n = 1 --> n=1