Question 519099
let's p be the perimeter, a the area, l the length and w the width .

 since we are talking about a rectangle, p=2(l+w) and a=lw

  l is 3 yds longer than w, means l=w+3
  
 p=2(l+w)                                           
  =2(w+3+w)                                          
  =4w +6                                              
from this we have      w= (p-6)/4                   
 At this level, there are two possibilities.
   
  the first one, find the value of l and w and then a
   w=(p-6)/4= (42-6)/4 = 9 yds
   l= w+3= 9+3 =12 yds
then a= lw= 12*9= 108 yds^2

  the second one, express w as a function of p and   and we change the l into w+3 and we put both of them in the formula of the area

    a=lw                   
     =(w+3)w                              we know p=4w+6 , so w= (p-6)/4 
     = [(p-6)/4 +3] (p-6)/4
     = [ (42-6)/4 +3] (42-6)/4
     = 108 yds^2