[tex]a=-3,\ \ y=2\\\\a)\\\\(x+y)(x-y)=(-3+2)(-3-2)=(-1)*(-5)=5\\\\b)\\\\\frac{3xy+2}{2}= \frac{3*(-3)*2+2}{2}=\frac{-18+2}{2}=\frac{-16}{2}=-8\\\\c)\\\\x(2x+y^2)=-3(2*(-3)+2^2)=-3(-6+4)=-3*(-2)=6[/tex]
