Respuesta :

let the width be w and length be l and area be a.

l= 5 + 2w

now, area = length x breadth

=> a = l x b
=> 168 = (5+2w ) x w

=>168 = 5w + 2w^2

=>on factorising, w= 8 

hence dimensions : 21 x 8 mm

Otras preguntas