Answer
$y^2+5y+4$.
Work Step by Step
The given expression is
$=(y+4)(y+1)$
Distribute $(y+1)$ to each term of $(y+4)$.
$=y(y+1)+4(y+1)$
Use distributive property.
$=y(y)+y(1)+4(y)+4(1)$
Multiply.
$=y^2+y+4y+4$
Combine like terms.
$=y^2+5y+4$
Hence, the product is $y^2+5y+4$.
