Question

3l+y=5=5l, for l

Answer 1

wait I think you wrote the problem wrong, is it
3l+y=5=5l
or
3l+y=5+5l

Answer 2

3L =y=5=5L, for L

Answer 3

you just wrote something completely different. is it
3L+y=5=5L
3L+y=5+5L
3L =y=5=5L
please pick one

Answer 4

the last one

Answer 5

ok, then
3L =y=5=5L
by the transitive property:
3L=5L
3/5=1
which is not true so the problem has NO SOLUTIONS
I am highly suspicious that you wrote the problem incorrectly though.