Answer
$3y^2-7y-40$.
Work Step by Step
The given expression is
$=(y-5)(3y+8)$
Distribute $(3y+8)$ to each term of $(y-5)$.
$=y(3y+8)-5(3y+8)$
Use distributive property.
$=y(3y)+y(8)-5(3y)-5(8)$
Multiply.
$=3y^2+8y-15y-40$
Combine like terms.
$=3y^2-7y-40$
Hence, the product is $3y^2-7y-40$.