Question 51265
(30+2X)(40+2X)=1800 OR 1200+80X+60X+4X^2=1800 OR 4X^2+140X-600=0 OR 

X^2+35X-150=0 OR x=3.86 ft wide walkway (using the quadratic equation)

proof (30+2*3.86)(40+2*3.86)=1800 or (30+7.72)(40+7.72)=1800 or 

37.72*47.72=1800 or 1800=1800