Isolate the z. Note the equal sign. Subtract 1/7z to both sides
1/7z (-1/7z) + 2 = -6/7z (-1/7z)
2 = -6/7z - 1/7z
Simplify. Combine like terms
2 = -7/7z
2 = -1z
Isolate the z. Divide -1 from both sides
(2)/-1 = (-1z)/-1
z = 2/-1
z = -2
-2 is your answer
hope this helps