Question

How do you solve `T=(3R)/(M-N)` for R?

Answer 1

Remember `a/b=c/d->ad=bc` (cross-product)

Explanation:

`T/1=(3R)/(M-N)->T*(M-N)=1*3R->`

`3R=T(M-N)->R=1/3 T(M-N)=(T(M-N))/3`

Answer 2

`R=(TM-TN)/3`

Explanation:

First of you need to multiply both sides by `M-N`;
`T(M-N)=(3R)/(M-N)(M-N)=TM-TN=3R`
Then you need to divide both sides by three;
`(TM-TN)/3=(3R)/3=(TM-TN)/3=R`
Hope that helps :)