Question 410830
Foil stands for F-first, O-outer, I- inner, L- last
what this means is that you are going to multiply the first terms in both parts
  F   (11x)(x)=11x^2
  O   (11x)(4y)=44xy
  I   (3y)(x)= 3xy
  L   (3y)(4y)= 12y^2
this would give you 11x^2+44xy+3xy+12y^2
now check to see if you have same terms if you do add them together.
  So, 44xy+3xy =47xy
   Answer= 11x^2+47xy+12y^2

hope this helps!