Hello!
In these types of equations, you would first need to distribute the numbers inside the parenthesis - according to PEMDAS.
-1/2 (2n + 4) + 6 = -9 + 4 (2n + 1)
(-1n - 2) + 6 = -9 + 8n + 4
Now that it's done, we need to combine like terms.
-n + 4 = 8n - 5
Next step is to move everything to it's appropriate places and make the variable equal to something, in other words, solve for n.
-n + 4 = 8n - 5
-9n = -9
Since the variable is negative and has a number of nine, we divide the whole equation by -9 in order to make it positive and leave "n" by itself.
-9n = -9
n = 1
Your answer would be 1.