Answer
$(x+y+z)(3x-2y-z)=3x^{2}+xy+2xz-2y^{2}-3yz-z^{2}$
Work Step by Step
$(x+y+z)(3x-2y-z)$
Evaluate the product indicated by multiplying all three terms of the first factor by every element in the second factor separately:
$(x+y+z)(3x-2y-z)=...$
$...=3x^{2}-2xy-xz+3xy-2y^{2}-yz+3xz-2yz-z^{2}=...$
Simplify by combining like terms:
$...=3x^{2}+xy+2xz-2y^{2}-3yz-z^{2}$