Question 363339
2l +2w = 30, or l+w = 15.  we have l = 15 - w.
Also, area is lw = 36.  By direct substitution, (15 - w)w = 36.
{{{15w - w^2 = 36}}},
{{{w^2 - 15w+36 = 0}}},
{{{(w-3)(w-12) = 0}}},
w = 3 or w = 12.  The rectangle is 3"x 12".