Question

Solve each proportion.
(z-1)/3 = 8/(z+1)

Answer 1

`\frac{z-1}3 = \frac8{z+1}`

Eliminate the denominators.

`3(z+1)\cdot\frac{z-1}3 = 3(z+1)\cdot\frac8{z+1}`

`z^2 - 1 = 24`

Solve for
`z`.

`z^2 = 25`

`\boxed{z = \pm5}`