Question 560291
let the length be x
width = y

xy=480
x=480/y

(x+5)(y+5) is the area after increasing the sides

xy+5x+5y+25

xy+5x+5y+25- xy = 245

5x+5y=245-25
5x+5y=225
x+y=45
480/y +y = 45

multiply equation by y
480 +y^2=45y
y^2-45y+480=0

Find the roots of the equation by quadratic formula								
								
a=	1	,	b=	-45	,	c=	480	
								
b^2-4ac=	2025	+	-1920					
b^2-4ac=	105		
{{{	sqrt(	105	)=	10.25	}}}
{{{x=(-b+-sqrt(b^2-4ac))/(2a)}}}								
{{{x1=(-b+sqrt(b^2-4ac))/(2a)}}}								
x1=(	45	+	10.25	)/	2			
x1=	27.62							
x2=(	45	-10.25	) /	2				
x2= 	17.38

sides are 27.62 & 17.38m

							
The Perimeter=2*( 27.62 + 17.38)

= 90 meters