Question 193039
exactly  right

lets  review
(y+1)(y-3)(y-4)
foil  ist  2  terms
(y^2 -3y+y-3)(y-4)
(y^2-2y-3)(y-4)
rearrange, commutative  property
(y-4)(y^2-2y-3)
now  use  distribution
(y)(y^2-2y-3)  - (4)(y^2-2y-3)
y^3-2y^2-3y -4y^2+8y+12
combine  like  terms
y^3-6y^2+5y+12    ANSWER
Yes  we  prefer  vertical  allignment,  but  extremely  hard  to  type
check  let  y=0,,,original 1*-3*-4=12
answer,,,,12=12  ok
check  again  with  y=1
original,,,2*-2*-3=12
answer,,,,1-6+5+12=12  ok

again,  with  practice  this  moves  right  along
(x+1)(x+1)(x+1)
(x+1)(x^2+2x+1)
x(x^2+2x+1)+1(x^2+2x+1)
x^3 +2x^2+x +x^2+2x+1
x^3 +3x^2+3x+1  ANSWER
check  using  y=0
0riginal  ,,,1  answer,,,1,,,,ok
with y=2
answer,,,27,,,answer8+12+6+1=27

KEEP  UP  the  good  work,,,,it  just  takes  a  little  practice