Question 293223
Let the width  = {{{x}}}
Let the length = {{{y}}}
Let the perimeter = {{{P}}}
Let the area = {{{A}}}
{{{P = 60}}}
{{{60 = 2x + 2y}}}
{{{2y = 60 - 2x}}}
{{{y = 30 - x}}}
{{{A = x*(30 - x)}}}
{{{A = -x^2 + 30x}}}
It is given that {{{A <=144}}} ft2
{{{144 = -x^2 + 30x}}}
{{{144 = x*(-x + 30)}}}
I'll take a guess {{{x = 10}}}
{{{144 = 10*(-10 + 30)}}}
{{{144 = 200}}}
I'll try {{{x = 8}}}
{{{144 = 8*(-8 + 30)}}}
{{{144 = 8*22}}}
{{{144 = 176}}}
I'll try {{{x = 6}}}
{{{144 = 6*(-6 + 30)}}}
{{{144 = 6*24}}}
{{{144 = 144}}} OK
Next,
{{{x = 4}}}
{{{144 = 4*(-4 + 30)}}}
{{{144 = 104}}}
I deduce that {{{x <=6}}}
and
{{{y >= 24}}}
Either side must be less than or equal to 6
or greater than or equal to 24