How would I make z the subject of the formulae:

x=y(z-y)/z

(z-y)/z = 1 - (y/z) = x/y

y/z = 1 - (x/y)= (y-x)/y
z/y = y/(y-x)
z = y^2/(y-x)

To make z the subject of the formula, we want to isolate z on one side of the equation by performing a series of algebraic manipulations. Here's how you can do it step by step:

1. Start by multiplying both sides of the equation by z to eliminate the denominator:
xz = y(z - y)

2. Expand the brackets on the right side of the equation:
xz = yz - y^2

3. Move the term yz to the left side of the equation by subtracting yz from both sides:
xz - yz = -y^2

4. Factor out z on the left side of the equation:
z(x - y) = -y^2

5. Finally, divide both sides of the equation by (x - y) to solve for z:
z = -y^2 / (x - y)

So the formula with z as the subject is z = -y^2 / (x - y).