Question 912680
w for width of the flower garden
L for length of the flower garden
L=w+6


Note that walkway area, garden area, width, length all UNKNOWN.


Combined Area of Walkway and Garden:  {{{(w+2*4)(L+2*4)=(w+8)(L+8)=(w+8)(w+6+8)}}}
{{{(w+8)(w+14)}}}.


Area of the garden:  {{{wL}}}, or {{{w(w+6)}}}.


Perimeter of combined walk and garden:  {{{2(w+8)+2(w+14)=2w+16+2w+28}}}
{{{4w+44}}}.


Your two questions seem unclear, but more specific questions can be analyzed.
"Relationship between width of garden and one quantity or another".


Just the walkway area: {{{(w+8)(w+14)-wL}}}
{{{(w+8)(w+14)-w(w+6)}}}
{{{w^2+22w+112-w^2-6w}}}
{{{16w+112}}}---the walkway area, just walkway.