so our original equations would be..
[tex]2y + 2(y - 4) = p \: (perimeter)[/tex]
[tex]y \times (y - 4) = l \: (area)[/tex]
(a) perimeter in terms of y
[tex]y = \frac{p + 8}{4} [/tex]
(b) area in terms of y
*I'm actually not sure about b.. sorry*
(c) if perimeter = 28, find length
[tex]28 \div 4 = 7[/tex]
[tex]7 \times 7 = 49[/tex]
[tex]l (area)= 49[/tex]