Question 987607
Why need any "apps"?  This does not need anything complicated.  You just made an arithmetic mistake.


{{{y/4+1=c}}}   (Stay with one case level or the other.)
{{{4(y/4+1)=4c}}}
{{{y+4=4c}}}
{{{y+4-4=4c-4}}}
{{{y=4c-4}}}