Question 1105893
I'll choose the variation constants to be k and r.


{{{system(c=kd,and,d=re)}}}


Substitute.
{{{c=k(re)}}}
{{{c=(kr)e}}}


We could really use just one single variable for {{{kr}}}.
Let {{{K=kr}}}.


Now {{{highlight(c=Ke)}}}.



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when c=4 when e=12,find c when e=3
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{{{4=K*12}}}


{{{K=4/12}}}

{{{K=1/3}}}


Model for the problem description is {{{highlight(c=(1/3)e)}}}.


Let e=3.
{{{c=(1/3)*3}}}

{{{highlight_green(c=1)}}}