(1)2(x2y-3xy2)-2(3xy2-x2y)=2xy(x-3y)-2xy(3y-x)=4xy(x-3y)=4*1/2*2(1/2-3*2)=-22
(2)x2+(-x2+3x)-2(x-3x2)=3x-2x+6x2=x+6x2=(-1)+6=5
(3)4x-9x+X=3,即-4x=3,所以x=-3/4
(4)3-2(5-y)= -(2y+3),即3-10+2y=-2y-3,即2y+2y=-3-3+10,即4y=4,所以y=1
(5)3(2x-1)-2x=10,即6x-3-2x=10,即4x=13,所以x=13/4