Question 965007
let width =x cm
then length = x-12 cm
given that area of rectangle = 160 sq cm
               l* b = 160
  (x-12)*x= 160
  x^2 - 12*x= 160
 x^2 -12*x -160=0
 x^2 -20*x+8*x -160 =0
 x(x-20)+8(x-20) = 0
 (x-20)*(x+8) = 0
  x=20   x=-8 (negative) 
  hence width = 20 cm
        length = 20-12 =8cm