14 = 64 - 5z
First: You have to get rid of the 64. That means you use the inverse operation which is if it is a positive number then you subtract it by the original number. Then, after you complete that operation you do 14 - 64 which equals -50.
So now you have.
-50 = -5z
Lastly all you need to do is divide -50 by -5 which gets you 10.
The original part was that you either divide or multiply if it has a variable then you divide it by itself without the variable.
The solution to your problem is: z = 10.