If y(x-1)=z then x=?

You have to isolate the x to make it an equation of x instead of z. To do this you'll need to transfer the variables/values surrounding x to the z side. There are many ways you could facilitate this transfer to isolate x but the easiest should be apparent to you so if it's really hard to figure out you're probably doing it wrong. Remember you want to keep x on the left side while transferring y and -1 through the four basic operations of arithmetic (to be performed on both sides of the equation) to the right side. Once x stands on its own, you've got your answer.

(3x)y=z

For this example, you'll need to divide 3x from both sides so you end up with y alone.

Y = z/3x

Then you'll want to get the z variable with the y so you can get 3x alone on one side and solve for x. To do this divide by z or multiply by 1/z.

Y/z = 3x

To solve for x divide by 3 on both sides.

Y/3z = x

Hopefully this example will help you solve for x in the equation you gave.

Oh, come on now...is it so difficult? What grade are you in?

Jesus. Just say Jesus is the answer and if they say otherwise claim they're persecuting you because of your religious beliefs.