Question 952331
Easier to form two equations before simplifying into fewer.

{{{6/1=x/y}}} using x for rabbits and y for chickens.


2 legs per chicken;
4 legs per rabbit;
Those are ratios.
{{{2*(legs/chicken)}}} and {{{4*(legs/rabbit)}}}.


Account for the total number of legs:
{{{4x+2y=54}}}.


You have a system which you can use for answering the question.
{{{highlight(system(6=x/y,4x+2y=54))}}}.


....