# Thread: make y the subject...

1. ## make y the subject...

$3y/(y-1) = x$

I can't seem to make y the subject of the above formula....I must be having some kind of mental lapse here!

2. Originally Posted by Ant
$3y/(y-1) = x$

I can't seem to make y the subject of the above formula....I must be having some kind of mental lapse here!
$\frac{3y}{y - 1} = x$

$\Rightarrow 3y = x(y - 1) = xy - x$

$\Rightarrow 3y - xy = -x$

$\Rightarrow y (3 - x) = -x$

$\Rightarrow y = \frac{-x}{3 - x} = \frac{x}{x - 3}$.

3. thankyou!