(1)3x²-[5x-(1/2x-3)+2x²]
=3x²-(5x-1/2x+3+2x²)
=3x²-9/2x-3-2x²
=x²-9/2x-3
(2)2(x+y)-1/4(x+y)+2/3(x-y)
=2x+2y-1/4x-1/4y+2/3x-2/3y
=29/12x+13/12y
(1)3x²-[5x-(1/2x-3)+2x²]
=3x²-(5x-1/2x+3+2x²)
=3x²-9/2x-3-2x²
=x²-9/2x-3
(2)2(x+y)-1/4(x+y)+2/3(x-y)
=2x+2y-1/4x-1/4y+2/3x-2/3y
=29/12x+13/12y