Answer :
let x be the length loner
(15+x)*(13+x)=255
x^2+28x+195=255
x^2+28x-60=0
( x-2)(x+30)=0
x=2 or x=-30 (rejected)
Therefore the length longer is 2 m
(15+x)*(13+x)=255
x^2+28x+195=255
x^2+28x-60=0
( x-2)(x+30)=0
x=2 or x=-30 (rejected)
Therefore the length longer is 2 m