Упростите выражения
(2-3х-4х^2)+(--х^2+3х+2)=
(5х+у^2-2)-(x^2-3y)=
(3х+0,25х^3у-2 3/4ху^2)*(-4х^2у)=
(1+3х)*(4-х+х^2
(a-8)*(a+8)-(3a+2)*(3a+1)