Find the product.
3y^2 z(2y^2 z + 4yz - y + z)
=6y^(4z) + 12y^(1+2z)z - 3y^(1+2z) + 3zy^(2z)?
3y^2 z(2y^2 z + 4yz - y + z)
=6y^(4z) + 12y^(1+2z)z - 3y^(1+2z) + 3zy^(2z)?
