Question

How to make x the subject?

`A-x=(xr)/t`

Answer 1

`x = (At)/(r+t)`

Explanation:

Given:

`A-x=(xr)/t`

Mutiply both sides of the equation by `t` to get:

`At-xt = xr`

Add `xt` to both sides to get:

`At = xr+xt`

`color(white)(At) = x(r+t)`

Divide both ends by `(r+t)` and transpose to get:

`x = (At)/(r+t)`