Can you be a little more specific?
Do you mean that if is a root, then the other root is ?
Then find the corresponding ?
Factorising is the fastest way.
Here the sum of the roots=4.
One is 3 times the other, so the sum of the roots is 4 times the smaller root.
Smaller root = 4/4.
If you had an expression that was difficult to factorise,
you could proceed as follows.....
The solutions (roots) of a quadratic equation
One root is
The other root (a quadratic has at most 2 roots) is
First re-arrange your equation to
If one root is 3 times the other, the bigger root must be the one with the +
The denominator is common, so it is irrelevant.